arm
arm — noun
1. the long body part that runs from your shoulder to your hand, with an elbow in t
the long body part that runs from your shoulder to your hand, with an elbow in the middle, used for lifting, carrying, and reaching.
Sami broke her left arm when she fell off the swing.
common collocation: break + arm
The little boy held a teddy bear under his arm.
preposition: under + arm
My grandmother put her arms around me and gave me a long hug.
put one's arms around + person
Esme waved his arms wildly to get the taxi driver's attention.
wave + arms
After painting the ceiling for an hour, my arms really started to ache.
- break an arm
- fold your arms
- raise your arm
- under your arm
- in someone's arms
Usage Note
Often appears with possessive pronouns (my, his, her) and with verbs of motion (raise, fold, stretch, wave). The plural 'arms' meaning weapons is a separate sense, not this one.
Common Mistakes
2. the raised side section on a chair or sofa where you place your elbow, or the tu
the raised side section on a chair or sofa where you place your elbow, or the tube of fabric on a shirt or coat that wraps around your arm.
Grandpa rested his cup of tea on the arm of the old leather chair.
the arm of + chair / sofa
There was a small tear in the right arm of Tomoko's wedding dress.
the arm of + clothing item
The cat liked to sleep curled up on the arm of the sofa.
Otto rolled up the arms of his sweater before washing the dishes.
plural use for both sides of clothing
- the arm of a chair
- the arm of a sofa
- the arm of a jacket
Usage Note
Almost always followed by 'of' + the chair, sofa, jacket, or shirt it belongs to. 'Sleeve' is the more common word for the clothing meaning in everyday British and American English.
3. in the phrase 'arm in arm', describing two people walking close together with on
in the phrase 'arm in arm', describing two people walking close together with one person's bent elbow hooked through the elbow of the other.
The bride and her father walked arm in arm down the aisle.
fixed phrase: arm in arm
The two old friends strolled arm in arm along the riverside path.
arm in arm + verb of walking
We saw an elderly couple walking arm in arm through the park at sunset.
Uri and her best friend posed arm in arm for the graduation photo.
- walk arm in arm
- stroll arm in arm
Grammar Patterns
arm in arm
Usage Note
Only appears in the fixed phrase 'arm in arm'. Distinguish from 'hand in hand' (holding hands) — 'arm in arm' specifically means elbows are linked.
Common Mistakes
4. in the phrase 'on someone's arm', referring to a date or romantic partner who sh
in the phrase 'on someone's arm', referring to a date or romantic partner who shows up beside you at a public event such as a premiere or gala.
The actor arrived at the premiere with a famous singer on his arm.
on + possessive + arm
The young diplomat showed up at the ball with his fiancée on his arm.
Sofia walked into the gala with a handsome stranger on her arm.
Reporters always notice who is on the senator's arm at charity dinners.
common in celebrity / society reporting
- arrive with someone on your arm
- on the arm of
Grammar Patterns
on someone's arm
Usage Note
Almost always used about formal or public events (premieres, galas, weddings). Can carry a subtly old-fashioned or tabloid tone, suggesting the companion is being shown off.
5. a long, thin piece sticking out from a larger machine or device, often one that
a long, thin piece sticking out from a larger machine or device, often one that swings, lifts, or rotates to do a specific job.
The robot arm in the factory picks up car doors and welds them in place.
robot arm in industrial use
A long mechanical arm lowered the camera into the deep underwater cave.
mechanical arm + verb of action
The needle on the record player sits at the end of a thin metal arm.
Engineers replaced the broken arm of the crane before lifting any more steel beams.
the arm of + machine
- robot arm
- mechanical arm
- the arm of a crane
Usage Note
Often paired with adjectives like 'mechanical', 'robotic', or 'long', or with the name of the machine ('the arm of the crane'). Subject is usually inanimate.
6. a slim strip of sea, lake, or land that reaches out from, but stays attached to,
a slim strip of sea, lake, or land that reaches out from, but stays attached to, a bigger area.
Our small boat sailed up a quiet arm of the sea between two green islands.
arm of the sea / lake
A narrow arm of the lake reaches deep into the pine forest north of the village.
The fishermen sheltered in a sandy arm of land that curved out into the bay.
arm of land
On the map, you can see a long arm of the river snaking through the desert.
- an arm of the sea
- an arm of the lake
- an arm of land
Usage Note
Almost always followed by 'of the sea / lake / river' or 'of land'. More common in geography texts and travel writing than in everyday speech.
7. a separate part of a big company, government, or group that handles one particul
a separate part of a big company, government, or group that handles one particular kind of work or covers one area.
The publishing arm of the company earns more money than its newspaper division.
the [field] arm of + organization
The investigation was led by the intelligence arm of the federal police.
intelligence arm / military arm
The charity opened a new arm in Kenya to deliver clean water to rural villages.
The research arm of the university focuses entirely on cancer treatments.
- the research arm
- the military arm
- the investment arm
- the publishing arm
Usage Note
Subject is usually an institution (company, government, charity, university). Often modified by an adjective naming the function: 'research arm', 'military arm', 'investment arm'.
8. in sports talk, the strength and accuracy a player has when throwing a ball, esp
in sports talk, the strength and accuracy a player has when throwing a ball, especially in baseball or American football.
The young pitcher has an amazing arm and can throw the ball over 95 miles an hour.
have + adjective + arm
Coaches praised the quarterback for his strong arm and quick decisions.
strong arm in sports context
Even at age forty, the outfielder still had a great arm from deep right field.
Scouts say the boy from Osaka has the best arm of any high school catcher this year.
- a strong arm
- a good arm
- a great arm
- throw
used as a noun: 'a great throw', focuses on one action rather than overall ability
Usage Note
Subject is always a player; verb is almost always 'have' plus an adjective ('a good arm', 'a strong arm', 'a great arm'). Mostly heard in baseball, American football, and cricket commentary.
Common Mistakes
(with) arms akimbo
idiomA position where your hands are on your hips and your elbows point outward.
The angry teacher stood with arms akimbo, waiting for an answer.
Why are you standing there with arms akimbo?
as long as your arm
idiomUsed to describe something that is extremely long.
The grocery list was as long as your arm.
I have a to-do list as long as your arm.
a babe in arms
idiomA very young baby who cannot walk yet.
She was just a babe in arms when her family moved.
The photo shows him as a babe in arms.
bear arms
idiomTo serve as a soldier or to fight in a war.
Many young men were forced to bear arms during the war.
He chose to bear arms for his country.
chance your arm
idiomTo take a risk even though you will probably fail.
She decided to chance her arm and apply for the job.
I'll chance my arm and ask for a raise.
To cost or pay a very large amount of money.
The new car cost an arm and a leg.
We paid an arm and a leg for that vacation.
fold your arms
idiomTo place one arm over the other and hold them against your body.
He folded his arms and looked at me angrily.
Why did you fold your arms during the meeting?
To put your arms around someone and hold them close to your body.
She folded her crying child in her arms.
He folded her in his arms and whispered softly.
Used to say that someone would give up a lot to have or do something they really want.
I would give my right arm to meet my favorite author.
She'd give her right arm for a chance to travel.
To avoid having a close relationship with someone.
She keeps her colleagues at arm's length.
Why do you keep him at arm's length?
The power or authority that something has, especially when it reaches far.
No one can escape the long arm of the law.
The long arm of the company reached every town.
a shot in the arm
idiomSomething that gives encouragement or needed help to someone or something.
The new funding was a shot in the arm for the project.
Her kind words gave me a shot in the arm.
twist somebody’s arm
idiomTo persuade or force someone to do something.
I didn't want to go, but my friends twisted my arm.
She twisted his arm until he agreed to help.
with open arms
idiomIn a very happy and welcoming way.
The community welcomed the new family with open arms.
She greeted her old friend with open arms.
arm — verb
1. to give a person, group, or country guns, bombs, or other weapons, or to pick up
to give a person, group, or country guns, bombs, or other weapons, or to pick up weapons yourself.
The government decided to arm the local police with stun guns instead of pistols.
arm + someone + with + weapon
Rebel fighters armed themselves with rifles taken from an abandoned military base.
arm yourself with + weapon
Western countries continued to arm the small nation against its larger neighbour.
arm + country + against
The guards were armed and stood watch at every gate of the palace.
passive: be armed
- arm someone with
- heavily armed
- arm yourself
- disarm
to take weapons away from someone or something
Grammar Patterns
arm someone with something
arm yourself
Usage Note
Frequently used in the passive ('be armed') or with reflexive pronouns ('arm themselves'). The thing given is introduced by 'with'. Distinguish from sense 2: this sense always involves real weapons.
Common Mistakes
2. to give someone the equipment, facts, or skills they need so that they are ready
to give someone the equipment, facts, or skills they need so that they are ready to do a task or face a challenge.
The workshop armed new teachers with practical strategies for noisy classrooms.
arm + person + with + skills/tools
Uri arrived at the meeting armed with charts, photos, and three years of sales data.
armed with + facts/evidence
The journalist went into the interview armed with tough questions about the contract.
armed with + abstract noun
Parents can arm their children with simple safety rules before the school trip.
- armed with information
- armed with knowledge
- armed with evidence
- arm someone with skills
Grammar Patterns
arm someone with something
Usage Note
Very often in the passive form 'armed with' followed by an abstract noun (information, knowledge, evidence, questions). Distinguish from verb sense 1: here the 'weapon' is figurative — facts, skills, or tools, not real arms.
Common Mistakes
up in arms
idiomvery angry and complaining loudly about something, often as a group.
Local parents were up in arms about the sudden closure of the village school.
Fans were up in arms when the band cancelled the Tokyo concert with no refund.
take up arms
idiomto start using weapons in order to fight, usually in a war or rebellion.
Thousands of farmers took up arms against the corrupt regional governor.
The villagers refused to take up arms and chose peaceful protest instead.
with open arms
idiomin a warm and friendly way, showing that you are very happy to welcome someone.
The Rohan family welcomed the exchange student with open arms.
After ten years away, Otto was greeted with open arms by his old neighbours.
twist someone's arm
idiomto put strong pressure on a person until they agree to do something they didn't really want to do.
I had to twist Marco's arm a little, but he finally agreed to sing at the wedding.
Nobody had to twist my arm to come on a free trip to Kyoto.
to be extremely expensive.
Renting a flat in central Taipei can cost an arm and a leg these days.
The handmade leather jacket cost Lisa an arm and a leg, but she wears it every winter.
at arm's length
idiomkeeping someone or something a small but clear distance away, especially to avoid getting too close emotionally or in business.
The company kept the noisy investor at arm's length during the merger talks.
After the argument, Mei held her cousin at arm's length for almost a year.
Word family
Synonym discussion
Sense: noun/1
All three words point to the same body part, but they sit at very different levels of register. 'Arm' is the everyday word every learner needs first — used in conversation, news, fiction, and medical contexts alike, and the only natural choice for greetings, hugs, sports, or injuries ('She broke her arm'). 'Limb' is more formal and technical; it covers both arms and legs, and tends to appear in medical writing, news reports about accidents, and biology ('doctors saved all four of his limbs'). 'Forelimb' is strictly scientific, used by zoologists and veterinarians for animals, almost never for humans in everyday speech ('a horse's forelimbs', not 'the child's forelimbs'). Quick rule: in normal life, choose 'arm'; in a hospital report, 'limb'; in a biology paper, 'forelimb'.
Common collocations
Nouns
- arm of a chair
- arm of a sofa
- arm of the sea
- arm of the law
- robot arm
Adverbs
- heavily (armed)
- arm in arm
Phrases
- fold your arms
- open your arms
- raise your arm
- twist someone's arm
- cost an arm and a leg
Prepositions
- under your arm
- in someone's arms
- on someone's arm
- with open arms
Etymology
The body-part sense of 'arm' comes from Old English 'earm', a word shared with Old Norse 'armr' and German 'Arm', all going back to a Proto-Germanic root meaning the upper limb. The weapon and verb senses look identical in modern spelling but actually arrived later by a separate route: through Old French 'armes' from Latin 'arma' meaning weapons or tools of war. The two streams settled into one English word in the Middle Ages, which is why today's 'arm' covers both a body part and the act of taking up weapons.