back
back — verb
1. to publicly say you agree with a person, plan, or idea, or to give them money so
to publicly say you agree with a person, plan, or idea, or to give them money so they can succeed.
Three local banks agreed to back Xander's small bakery with a loan.
back + business: financial support
Most teachers in the school backed the new lunch program for poor students.
back + plan: public approval
Her parents backed her decision to study music in Vienna.
The mayor refused to back the protest after seeing the broken windows.
negative: refused to back
A wealthy uncle is backing the young singer's first album.
- back a candidate
- back a proposal
- back a plan
- back a project
- fully back
- publicly back
Grammar Patterns
back + noun (person/plan/proposal)
Usage Note
Object is usually a person, plan, project, candidate, or business. Distinguish from sense 3 (MOVE BACKWARDS): only this sense takes an idea or proposal as object.
Common Mistakes
2. to put money on a horse, team, or player, hoping they win so that you receive mo
to put money on a horse, team, or player, hoping they win so that you receive more money than you spent.
Otto backed a grey horse called Lucky Star and won fifty pounds.
back + horse name
Many fans backed Brazil to win the World Cup that summer.
back + team + to-infinitive
I never back the favourite because the prize money is too small.
Old men sat in the corner of the pub, backing horses on their phones.
- back a horse
- back the favourite
- back the underdog
- back a winner
- bet on
more common in everyday speech
- wager on
more formal or written
- stake money on
emphasises the amount risked
Grammar Patterns
back + horse/team/player
Usage Note
Common in British English in horse racing and football contexts. Object is the competitor, not the event itself: you back a horse, not a race.
Common Mistakes
3. to move in reverse, with the rear part going first, or to make a vehicle or anim
to move in reverse, with the rear part going first, or to make a vehicle or animal do this.
Nikolai slowly backed the truck into the narrow garage.
back + vehicle + into: reversing
The boy backed away from the angry dog without turning around.
intransitive: back away from
Please back your chair a little so I can open the drawer.
The thief backed slowly out of the shop, watching the door.
back + out of + place
Wairimu backed her bicycle off the path to let the runners pass.
- back away
- back up
- back into
- back out of
- back slowly
- advance
to move forward, often with purpose
Grammar Patterns
back + noun + into/out of/away from
back + adverb (away, up)
Usage Note
Almost always used with a direction word (away, up, into, out of, off). Bare 'back the car' alone is rare; speakers usually add 'up' or a destination.
Common Mistakes
4. to attach a layer of cloth, paper, or other material to an object's rear side so
to attach a layer of cloth, paper, or other material to an object's rear side so it becomes stronger or thicker.
The old map was backed with thin cotton cloth to keep it from tearing.
passive: be backed with + material
Wairimu backed each photograph with stiff card before putting it in the album.
back + object + with + material
The picture frame was backed with brown paper and a small wire hook.
Workers backed the wooden boards with metal sheets to make the door safer.
- backed with cloth
- backed with card
- backed with paper
- backed with metal
Grammar Patterns
be backed with/by + material
Usage Note
Frequently passive. The pattern is 'X is backed with Y', where Y is the added layer. Distinguish from sense 1 (SUPPORT): this sense never takes a person as object.
Common Mistakes
back — noun
1. for an object, room, or building, the side that lies farthest from its face, ent
for an object, room, or building, the side that lies farthest from its face, entrance, or display side — for example, the rear wall of a classroom, the boot of a car, or the reverse of a printed page.
Mei wrote her phone number on the back of the receipt.
the back of [paper/object]
The children sat at the back of the school bus and waved at us.
at the back of [vehicle/room]
There is a small garden at the back of our house.
The recipe is printed on the back of the cereal box.
on the back of [container]
Nikolai found the index in the back of the textbook.
in the back of [book]
- at the back
- in the back
- the back of the room
- the back of the book
- front
the directly opposite area
Grammar Patterns
the back of [something]
at the back
Usage Note
Frequently appears with the prepositions 'at', 'in', 'on', or 'to', and almost always with 'the'. Distinguish from sense 6 (body part): this sense is about objects and places, not anatomy.
Common Mistakes
2. in the phrase 'back to back', describing two people or things positioned with th
in the phrase 'back to back', describing two people or things positioned with their rear sides touching or pointing toward each other, so they face away in opposite directions.
The twins stood back to back so their mother could measure who was taller.
stand back to back
Xander and her sister sat back to back on the rug, leaning against each other.
sit back to back
The two soldiers fought back to back to defend each other from every direction.
Place the two sofas back to back to divide the living room into two zones.
place [things] back to back
- stand back to back
- sit back to back
- place back to back
- rear to rear
rare; only in technical descriptions
- face to face
describes two people or things turned toward each other
Grammar Patterns
stand/sit back to back
Usage Note
Always used as the fixed phrase 'back to back', not as a single noun. Distinguish from sense 3 ('back-to-back' meaning consecutive in time): this sense is about physical position.
Common Mistakes
3. in the phrase 'back to back', used when several events, games, or activities fol
in the phrase 'back to back', used when several events, games, or activities follow each other directly with no gap or pause in between.
Daniel had three meetings back to back and barely had time for lunch.
[events] back to back
Our team won two championships back to back in 2024 and 2025.
win [titles] back to back
The cinema played both films back to back, so the show ended at midnight.
play [films] back to back
Wairimu worked four shifts back to back at the cafe over the weekend.
work [shifts] back to back
- back-to-back meetings
- back-to-back wins
- back-to-back episodes
- back-to-back shifts
- consecutive
more formal, typically used as an adjective before the noun
- in a row
informal; same idea, more conversational
- spaced out
with breaks or gaps between events
Grammar Patterns
[event] back to back
Usage Note
Used as an adverbial phrase after the noun or verb. Distinguish from sense 2 (physical position): here 'back to back' refers to time order, not orientation.
Common Mistakes
4. in the phrase 'back to front', describing clothing or an object that has been pu
in the phrase 'back to front', describing clothing or an object that has been put on or arranged the wrong way round, so that the rear side is now pointing forward.
Otto realised at school that he had put his sweater on back to front.
put on [clothing] back to front
The toddler wore his shoes back to front and giggled at his clumsy steps.
wear [shoes] back to front
Wairimu hung the painting back to front by mistake and only noticed at dinner.
Dad had his cap on back to front, just like the kids on the skateboard team.
[have something] on back to front
- wear back to front
- put on back to front
- hat back to front
- backwards
common in American English for the same meaning
- the wrong way round
informal British phrase with the same meaning
- the right way round
with the front facing forward as intended
Grammar Patterns
wear/put on [clothing] back to front
Usage Note
More common in British English; American speakers often say 'backwards' instead. Distinguish from sense 2 ('back to back'): that describes two things, this describes one item turned the wrong way.
Common Mistakes
5. the upper, outer surface of a hand — the side opposite the palm, where you can u
the upper, outer surface of a hand — the side opposite the palm, where you can usually see knuckles, veins, and sometimes hair.
Xander wiped a tear from her cheek with the back of her hand.
the back of [your] hand
The nurse pressed the back of her hand against the baby's forehead to feel for fever.
press the back of [one's] hand against
A small mosquito landed on the back of Ben's hand during the picnic.
Grandma kissed the back of my hand and smiled warmly.
kiss the back of [one's] hand
- wipe with the back of one's hand
- kiss the back of someone's hand
- dorsum
technical anatomical term; rare in everyday speech
- palm
the inner, soft side of the hand
Grammar Patterns
the back of [your] hand
Usage Note
Almost always appears as 'the back of [someone's] hand'. Common in idioms about familiarity ('know it like the back of your hand'), though that idiom is listed separately.
Common Mistakes
6. in people and many animals, the area behind the chest and stomach that runs from
in people and many animals, the area behind the chest and stomach that runs from the shoulders down to the hips, with the spine forming its central support.
Nikolai hurt his back lifting a heavy box at work yesterday.
hurt [one's] back
The little girl rode on her father's back through the shallow river.
on [someone's] back
Aunt Rosa lay on her back in the grass and watched the clouds drift by.
lie on [one's] back
The horse had a long white stripe down its back.
down [an animal's] back
Xander scratched her back against the rough bark of the tree.
scratch [one's] back
- hurt one's back
- lie on one's back
- carry on one's back
- scratch one's back
Grammar Patterns
[someone's] back
on [one's] back
Usage Note
Often takes a possessive ('my back', 'his back'). Subject of many fixed expressions about effort or burden ('break your back', 'turn your back on'). Distinguish from sense 1 (rear of objects): this sense is anatomical only.
Common Mistakes
7. the area between your shoulders and waist when you are talking about hurting, st
the area between your shoulders and waist when you are talking about hurting, straining, or damaging that body region — for example, after lifting something heavy or sitting badly for a long time.
Otto injured his back trying to lift a heavy box of books up the stairs.
collocation: injure / hurt + one's back
The nurse warned Grandma that gardening on her knees might damage her back.
Wairimu strained her back during the volleyball match and missed the next game.
pattern: strain + one's back during [activity]
Sitting at the office desk for ten hours has done something terrible to my back.
informal: do + [adjective] + to one's back
The builder twisted his back lifting bags of cement off the truck.
- hurt your back
- injure your back
- strain your back
- pull a back muscle
- twist your back
- throw out your back
- spine
the bony column itself; narrower and more clinical than back
- lower back
the region most often strained by lifting
Grammar Patterns
hurt/injure/strain + one's back
do + something + to one's back
Usage Note
Distinguish from sense 6 (the general body-part name): this sense focuses on the back as the place that is hurt or strained, and almost always appears with a verb of injury such as hurt, injure, strain, twist, pull, or damage.
Common Mistakes
8. in football and similar team sports, a player whose job is to stay near their ow
in football and similar team sports, a player whose job is to stay near their own goal and prevent opponents from putting the ball into the net, rather than attacking.
Diego plays at right back for the school football team and rarely lets a winger past him.
pattern: play (at) + [position] back
The coach moved Hannah from midfield to centre back after the injury.
collocation: centre back / left back / right back
Liverpool's left back made a perfect tackle just outside the penalty area.
A good back reads the game and stops attackers before they reach the goal.
definition-style sentence with the role of a back
Nikolai was the youngest back on the pitch but he marked the striker brilliantly.
- centre back
- left back
- right back
- full back
- play at back
Grammar Patterns
play (at) back
be a back
left/right/centre + back
Usage Note
Almost always appears with a position word in front of it (left, right, centre, full). Subject is typically a named player or a club. Distinguish from sense 9, which refers to a position behind the line of scrimmage in American football and rugby.
Common Mistakes
9. in rugby, or American-style football, a player who starts each play well behind
in rugby, or American-style football, a player who starts each play well behind the forwards — usually a quick runner expected to carry or pass the ball.
Tyler is the fastest back on the rugby team and almost always scores from open field.
subject is a named player + back as a position
The Eagles' running back broke through the defence for a forty-yard touchdown.
collocation: running back
Rugby backs need quick feet, sharp passing, and the courage to tackle bigger forwards.
the backs as a group of positions in rugby
Coach Reeves moved Jamal from quarterback to halfback last season.
Ohio State's young back caught the ball and sprinted past two defenders.
- running back
- halfback
- quarterback
- the backs
- rugby back
- running back
American football: a back whose main job is to run with the ball
- halfback
rugby / older football term: a back close to the scrum or line
Grammar Patterns
play (in the) backs
the backs
Usage Note
Distinguish from sense 8: that sense is a defender in football / soccer; this sense is a position behind the line in American football or rugby, where the role often includes running and passing the ball. Common compounds: running back, halfback, fullback, quarterback.
Common Mistakes
10. the upright piece on a chair, sofa, or bench that supports your shoulders and sp
the upright piece on a chair, sofa, or bench that supports your shoulders and spine while you are seated.
Mei hung her wet jacket over the back of the wooden kitchen chair.
pattern: the back of + [chair]
The old armchair has a soft padded back that makes long reading easy.
Dad leaned against the back of the sofa and closed his tired eyes.
collocation: lean against the back of [furniture]
The carpenter carved a pattern of leaves into the back of every dining chair.
This office chair has a high back to support your shoulders during long meetings.
pattern: high-backed / low-backed chair
- back of the chair
- back of the sofa
- high-backed chair
- padded back
- lean against the back
- seat
the flat part you sit on, opposite the back
Grammar Patterns
the back of + [chair / sofa / bench]
[adjective]-backed + [chair]
Usage Note
Subject is typically a piece of furniture with a built-in support (chair, sofa, bench, armchair). Often appears in compound adjectives such as high-backed, straight-backed, padded-back. Distinguish from sense 1 (the rear part of an object): the back of a chair is its support, not its rear face.
Common Mistakes
A thought that you are aware of but not actively thinking about.
At the back of her mind, Maya knew she had forgotten something important.
The fear of failure was always at the back of my mind during the exam.
When someone is not looking or is absent, so they cannot see what is happening.
As soon as the teacher's back was turned, the students started whispering.
The thief stole the wallet when the shopkeeper's back was turned.
the back of beyond
idiomA place that is very far away from towns and other people.
They bought a cottage in the back of beyond, miles from any shop.
My cousin lives on a farm in the back of beyond with no neighbors.
Done in a quick and rough way, without careful calculation or detail.
He estimated the cost on the back of an envelope during lunch.
The engineer made a back-of-the-envelope sketch of the new design.
back to back
idiomWith backs facing or touching each other; also means happening one after another.
The two friends sat back to back on the floor, drawing pictures.
The team played three games back to back over the weekend.
back to front
idiomWearing clothing with the back part where the front should be.
Little Tom put his shirt on back to front this morning.
Did you notice that your jacket is on back to front?
To be happy that someone or something is leaving or gone because you dislike them.
I was glad to see the back of that noisy old car.
The whole office was happy to see the back of the rude manager.
Doing something without someone's knowledge, often in a dishonest way.
They made plans behind my back and didn't invite me.
Sara was angry that her friend talked about her behind her back.
To keep annoying someone by asking or telling them to do something.
My boss is on my back about finishing the report by Friday.
Mom is always on my back to clean my room.
To finish the largest or most difficult part of a task.
We broke the back of the project by completing the research phase.
After three hours, I finally broke the back of the cleaning.
cover your back
idiomTo take actions to avoid future blame or criticism.
Always keep receipts to cover your back in case of disputes.
The lawyer advised her to document everything to cover her back.
To annoy or anger someone.
His rude comments really got my back up during the meeting.
Don't put her back up by criticizing her work.
To stop annoying someone, especially by criticizing or pressuring them.
I wish my parents would get off my back about my grades.
Get off my back! I'll do the dishes later.
To be ready to protect or support someone.
Don't worry, I've got your back if anyone tries to bully you.
In this team, we always have each other's backs.
To be in a difficult situation with few choices.
With debts piling up, the company had its back to the wall.
He had his back to the wall and had to accept the deal.
To be aware of everything happening around you, even things you cannot see.
My teacher must have eyes in the back of her head; she saw me pass a note.
You need eyes in the back of your head to watch these kids.
To know someone or something very well.
After living here for 20 years, I know this town like the back of my hand.
She knows the software inside out after using it for years.
The last small problem that makes you finally lose patience or give up.
When he arrived late again, it was the last straw and she fired him.
The broken printer was the straw that broke the camel's back for the frustrated staff.
To do something that will cause you trouble later.
By lying now, you are making a rod for your own back.
If you agree to do all the work, you're making a rod for your own back.
Immediately after something, often as a result.
The team won the championship off the back of a ten-game winning streak.
Sales increased off the back of a successful advertising campaign.
As a result of a success or achievement.
The company expanded on the back of strong quarterly profits.
Her promotion came off the back of her excellent project results.
Goods that are probably stolen, but the source is not admitted.
He bought a cheap phone that fell off the back of a lorry.
The suspiciously cheap goods might have come off the back of a lorry.
(flat) on your back
idiomLying in bed because you are sick or unable to move.
After the surgery, she was flat on her back for two weeks.
The flu put him on his back for several days.
Praise or approval for doing something well.
The manager gave her a pat on the back for her hard work.
You deserve a pat on the back for finishing the project early.
To praise someone or yourself for doing something well.
He patted himself on the back after passing the difficult exam.
The coach patted the players on the back for their victory.
To try to forget something unpleasant.
She pushed the painful memory to the back of her mind.
I tried to push my worries to the back of my mind during the movie.
To use a lot of effort and energy on a task.
If you put your back into it, you can finish the job by noon.
He really put his back into cleaning the garage.
Everything someone has, even what they need themselves, that they give to others.
He would give you the shirt off his back if you needed help.
She is so generous, she'd give you the shirt off her back.
a stab in the back
idiomAn act of betrayal by someone you trusted.
His criticism of me in the meeting was a real stab in the back.
She felt her friend's gossip was a stab in the back.
To betray someone who trusts you.
He stabbed his business partner in the back by stealing clients.
I can't believe she stabbed me in the back after all we've been through.
turn your back
idiomTo turn your body so that you are facing away from something.
She turned her back and walked away without saying a word.
When he turned his back, the child quickly hid the toy.
To ignore or reject someone or something, or to physically face away.
He turned his back on his family after the argument.
Many people are turning their backs on fast food for health reasons.
watch your back
idiomTo be careful and protect yourself from danger or harm.
In this neighborhood, you have to watch your back at night.
She told me to watch my back because there were rumors about me.
Criticism or negative comments that have no effect on someone.
His mother's scolding was like water off a duck's back to him.
The negative reviews were water off a duck's back for the confident singer.
If you help me, I will help you in return, often implying mutual benefit.
In politics, it's often you scratch my back and I'll scratch yours.
They made a deal: you scratch my back and I'll scratch yours.
back — adjective
1. located in the part of a place, building, or vehicle that is opposite the front,
located in the part of a place, building, or vehicle that is opposite the front, or further from the main road, town, or busy area.
Xander planted tomatoes and herbs in the back garden every spring.
attributive: back + noun (garden, door, room)
The cat slipped out through the back door before anyone noticed.
Two shy students always sat in the back row of the classroom.
collocation: back row / back seat
Grandma Lin keeps her old photo albums on a back shelf in the closet.
We took a quiet back road to avoid the traffic near the stadium.
extended sense: back road / back street (away from main routes)
- back door
- back garden
- back seat
- back row
- back room
- back road
- back yard
- front
directly opposite: front door, front row
Grammar Patterns
back + noun
Usage Note
Almost always used before a noun (attributive). You cannot say 'the garden is back' to mean rear-located; use 'at the back' instead.
Common Mistakes
2. describes money such as rent, wages, or taxes that someone still owes because th
describes money such as rent, wages, or taxes that someone still owes because the deadline for paying it has already passed.
The tenants finally paid two months of back rent in November.
collocation: back rent / back taxes / back wages
Mr. Alvarez owes the city nearly five thousand dollars in back taxes.
The factory workers are demanding three weeks of back pay from their boss.
passive-style object: demand / claim / receive back pay
Sasha used her bonus to cover the back interest on her student loan.
- back rent
- back taxes
- back pay
- back wages
- back interest
- overdue
broader; can describe library books, bills, or any late payment
- outstanding
formal; used for unpaid debts or invoices
- unpaid
neutral; emphasizes that no payment has been made yet
- current
describes payments that are up to date
Grammar Patterns
back + payment-noun (rent, taxes, wages, pay)
Usage Note
Used only before money-related nouns (rent, taxes, wages, pay, interest). Don't use it to mean 'paid in the past' — the key meaning is that the payment is late.
Common Mistakes
back — adverb
1. to the place, situation, or time where someone or something used to be — for exa
to the place, situation, or time where someone or something used to be — for example, returning home, putting an item where it belongs, or restoring an earlier condition.
Xander put the book back on the top shelf when she finished reading.
verb + back + on/in [location] for returning to original spot
After ten years in Tokyo, Otto moved back to his hometown in Italy.
move/go/come + back to + [place]
The power came back on at midnight after the storm passed.
phrasal pattern: come back on for restored function
Dad painted the old chair back to its original color last weekend.
Wairimu drove back to the office because she had forgotten her laptop.
- go back
- come back
- put back
- move back
- fight back tears
- again
'again' marks repetition; 'back' marks return to a prior state or place
- forward
of motion only; not a true opposite for the time/state senses
Grammar Patterns
verb + back to/from [place]
verb + back + adverb
Usage Note
Distinguish from sense 5 (FURTHER AWAY): this sense always implies returning to a known earlier point (place, state, or time), while sense 5 is purely directional with no prior reference point.
Common Mistakes
2. as a response to what someone has done to you — paying, giving, or doing somethi
as a response to what someone has done to you — paying, giving, or doing something equal in exchange, including kindness or revenge.
Nikolai paid his sister back the fifty dollars she had lent him last month.
pay + somebody + back + amount for repayment
When the older boy pushed him, Tomas pushed him back without a word.
verb + somebody + back for retaliation
Aunt Rosa always sends a small gift back whenever a neighbor brings her food.
I want to thank her properly and one day pay her kindness back.
- pay back
- give back
- hit back
- fight back
- get one's own back
- in return
more formal phrasing of the same idea
Grammar Patterns
verb + somebody + back
give/pay/hit + back
Usage Note
Often follows verbs of giving, paying, or hitting. The exchange may be positive (a gift, a favour) or negative (revenge, a punch). Distinguish from sense 3, which is specifically about verbal replies.
Common Mistakes
3. as an answer to a message, call, or question — used when someone responds after
as an answer to a message, call, or question — used when someone responds after the first person has already spoken or written.
Please call me back when you finish the meeting at four.
call + somebody + back for returning a phone call
Dr. Tomás emailed back within an hour to confirm the appointment.
email/write + back for replying to a message
When the teacher asked who broke the window, nobody answered back.
Lisa shouted hello, and her younger brother shouted back from the garden.
- call back
- write back
- email back
- answer back
- text back
- in reply
more formal; written contexts
Grammar Patterns
verb + back + (to somebody)
call/write/email + back
Usage Note
Common with verbs of communication: call, email, write, shout, answer, text. Differs from sense 2 in that the exchange is verbal or written, not an action or payment.
Common Mistakes
4. at an earlier point in time, often a long time ago — used to talk about events,
at an earlier point in time, often a long time ago — used to talk about events, memories, or recordings from the past.
Back in 1995, my grandparents bought this little house by the river.
back in + [year] for placing an event in the past
We watched the football match back later that evening on the recording.
watch/play + back for reviewing a recording
Two weeks back, the school organized a trip to the science museum.
[time period] + back, equivalent to 'ago'
Grandma still talks about her wedding day, way back in the spring of 1962.
- back in [year]
- way back
- watch back
- play back
- listen back
- ago
more neutral; preferred in writing for time periods
- previously
formal; written register
Grammar Patterns
back + in [year/period]
[time period] + back
Usage Note
With recordings (watch back, play back, listen back), it specifically means reviewing media after the live event. The pattern '[time period] back' is informal — 'two weeks back' is common in speech, but 'two weeks ago' is preferred in writing.
Common Mistakes
5. in a direction away from the front or away from something close, so that the per
in a direction away from the front or away from something close, so that the person or thing is now further from it.
Please stand back from the yellow line until the train stops.
stand/step + back + from + [thing] for moving away
The artist stepped back to look at the whole painting from a distance.
step back for gaining perspective
The small village sits back from the main road, hidden by tall trees.
Sit back in your chair, Wairimu, and try to relax for a moment.
- stand back
- step back
- sit back
- lean back
- pull back
- forward
direct opposite of direction
Grammar Patterns
verb + back + (from [thing])
stand/step/sit + back
Usage Note
Unlike sense 1, this sense does not imply returning to an earlier place — the subject simply ends up further from a reference point. Frequently with stand, step, sit, lean, pull.
Common Mistakes
Word family
Synonym discussion
Sense: verb/3
These four verbs all describe motion that ends up further from where you started, but they differ in scene and feeling. 'Back' is the everyday choice for short, controlled movement, especially with vehicles or careful steps: you back a car into a garage, or back away from a barking dog. 'Reverse' is more technical and often shows up on driving tests and engineering reports — it suggests a deliberate change of direction, frequently with machines. 'Retreat' carries the colour of fear, defeat, or strategic decision; armies retreat after losing ground, and shy people retreat into their rooms. 'Withdraw' is more formal still, suggesting a planned removal from a place, contest, or commitment, such as withdrawing from a race or from a meeting. So a driver backs the truck up the slope, an engineer reverses the engine, a soldier retreats under fire, and a candidate withdraws from the election.
Common collocations
Nouns
- back garden
- back door
- back seat
- back row
- back road
- back pay
- back taxes
Adverbs
- right back
- way back
- straight back
- all the way back
- fully back
- publicly back
Phrases
- back to back
- back to front
- back and forth
- behind one's back
- at the back of one's mind
- back in the day
Prepositions
- back to
- back from
- back into
- back onto
- at the back of
- in the back of
- on the back of
- behind the back of
Etymology
The word starts in Old English as 'bæc', meaning the rear part of a person's or animal's body. That noun comes from a much older Proto-Germanic root '*baką', shared with related forms in Old Norse and Old Saxon. From the body-part meaning, English speakers gradually stretched the word in two directions. First, they used it for the rear part of any object — the back of a chair, the back of a house — and then for spatial relations more generally. By the late Middle Ages, 'back' had also become an adverb meaning 'toward where one came from', which later spread to time ('back in 1900') and to actions done in return ('write back'). The verb senses, including 'support' and 'reverse a vehicle', grew out of these adverbial uses much later, mostly between the 1500s and 1800s.