lock
lock — verb
1. to put something inside a cupboard, box, room, or other enclosed space that is c
to put something inside a cupboard, box, room, or other enclosed space that is closed with a lock, in order to keep it safe or prevent others from taking it
Hannah locked her passport in the hotel safe before going to the beach.
lock + noun + in + [container]
The museum guard locked the rare paintings away in a vault every evening.
lock away + noun + in + [secure place]
Takeshi locked his bicycle to the metal railing outside the library.
lock + noun + to + [object]
All the important documents are locked in a cabinet that only the manager can open.
passive: be locked + in + [container]
Shirin locked her jewellery in a small box under the bed before the trip.
- lock away
- lock in a safe
- lock in a drawer
- lock to a railing
- secure
more formal; can mean locking or using other safety methods
- store away
focuses on putting aside for later, not necessarily using a lock
Grammar Patterns
be locked + adverb/preposition
lock something + adverb/preposition
Usage Note
A preposition or adverb (in, away, up, to) usually follows the object to show where or how something is secured. This sense is very often used in the passive voice, especially with in.
Common Mistakes
2. to turn a key, enter a code, or activate a device so that a door, window, gate,
to turn a key, enter a code, or activate a device so that a door, window, gate, or container stays closed and cannot be opened by someone who does not have the correct key or code
Gabriel locked the front door and checked all the windows before going to bed.
transitive: lock + [door/window/gate]
The bathroom door does not lock properly, so you need to pull it shut firmly.
intransitive: [thing] + locks
Paloma locked her car and walked towards the supermarket entrance.
transitive: lock + [vehicle]
Remember to lock your suitcase before putting it on the airport luggage belt.
Lotte heard her roommate lock the apartment door from the inside.
- lock the door
- lock the gate
- lock the car
- lock the suitcase
Grammar Patterns
lock something
something locks
lock + noun
Usage Note
When used intransitively (The door locks automatically), the subject is the thing being fastened, not the person doing the action. Many modern doors, cars, and windows can be described this way.
Common Mistakes
3. to become or cause something to become firmly stuck in one position so that it c
to become or cause something to become firmly stuck in one position so that it cannot move, or to fit two or more parts together so that they hold each other in place
The wheels of the shopping cart locked together, making it impossible to push.
intransitive: [parts] lock together
Dahlia locked her hands behind her head and leaned back in the chair.
transitive: lock + [body parts]
The two fighters locked arms and struggled for control of the match.
lock + [body part] — intertwined position
Adisa's knees locked with fear when he saw the snake on the path ahead.
intransitive: [body part] + locks — becomes stiff
The train doors locked automatically before the train pulled away from the station.
- lock together
- lock in place
- lock arms
- lock hands
- knees lock
- brakes lock
Grammar Patterns
something locks
lock + noun
lock together
lock in place
Usage Note
This sense can describe body parts (knees, elbows, hands, arms) becoming stiff and unable to move, or mechanical parts fitting together. The intransitive use — describing parts that lock by themselves — is very common.
Common Mistakes
lock away
phrasal verbTo put something in a safe place and close it with a lock.
Maya locked away her jewelry in a small safe.
Have you locked away the important documents?
lock down
phrasal verbTo close a building or area so that no one can enter or leave.
The school was locked down after a security threat.
Officers locked down the entire neighborhood for investigation.
lock in
phrasal verbTo make something fixed and unlikely to change.
We locked in a low interest rate for five years.
Did you lock in the price before the sale ended?
lock onto
phrasal verbTo find and follow a target using electronic equipment.
The missile locked onto the enemy aircraft.
The radar locked onto the incoming ship.
lock out
phrasal verbTo prevent someone from entering a place by locking the door.
Sara accidentally locked herself out of her car.
The landlord locked out the tenants for nonpayment.
lock up
phrasal verbTo close all doors and windows of a building with locks.
Please lock up the house before you leave.
The store manager locked up at midnight.
To start arguing or fighting with someone about something.
The two politicians locked horns over the new tax plan.
Why did you lock horns with your boss about the deadline?
lock — noun
1. An object, often made of metal or operated electronically, that is placed on a d
An object, often made of metal or operated electronically, that is placed on a door, drawer, or container to hold it closed until the correct key or code releases it.
Quan turned the key in the lock and pushed the heavy oak door open.
turn + key in the lock
The old wooden chest had a small brass lock that needed a special key.
Zuri bought a sturdy lock for her bicycle after the first one was stolen.
a lock for [object/vehicle]
Every night the security guard checks that each lock on the warehouse is secure.
Minho forgot the code to the electronic lock and called his landlord for help.
electronic lock + code
- turn the key in the lock
- a lock on something
- break a lock
- pick a lock
- electronic lock
- combination lock
- safety lock
- key
the tool used to open a lock, not the fastening device itself
Usage Note
The most common sense. Can refer to both traditional key-operated locks and modern digital or combination locks.
Common Mistakes
2. A water-filled chamber on a canal route that has doors on both sides; the water
A water-filled chamber on a canal route that has doors on both sides; the water inside can be raised or lowered so that vessels can travel between areas at different heights.
The tour boat entered the lock and waited for the water to rise slowly.
enter a lock / water level rises
The canal workers opened the heavy lock gates to let the barges pass through.
Élise watched the water fill the lock until the boat reached the higher level.
Pedro's grandmother used to operate the lock gates on the river when she was young.
operate the lock gates
- enter a lock
- lock gates
- fill the lock
- drain the lock
- a set of locks
- lock keeper
- canal lock
a fuller term that avoids confusion with door locks
- chamber
the enclosed section of water inside the lock itself
Usage Note
Canal locks are found on inland waterways. The verb phrase 'to lock through' describes the process of passing a boat through a lock.
3. Something so sure or definite that it can be depended on without doubt, especial
Something so sure or definite that it can be depended on without doubt, especially in competitions, business, or predictions.
With a ten-point lead, the team was a lock for the championship title.
a lock for [something] — certain to win
His promotion to manager is considered a lock by everyone in the office.
Investors treated the new company as a lock to deliver strong returns this year.
When the votes were counted, the election was a lock for the incumbent candidate.
a lock — certain outcome in competitions/predictions
- a lock for [something]
- a lock to [verb]
- considered a lock
- a virtual lock
- almost a lock
- sure thing
equally informal; used in betting and predictions
- certainty
more formal; used in general contexts without the betting connotation
- shoo-in
informal American English; specifically about an easy winner in a contest
- gamble
something risky, the opposite of a sure outcome
- question mark
an uncertain or unknown factor
Usage Note
Nearly always used in the pattern 'a lock for [something]' or 'a lock to [verb]'. Common in sports commentary, business analysis, and informal predictions. Avoid in formal academic writing.
Common Mistakes
4. A small bunch of hairs, especially one that naturally curls or has been shaped i
A small bunch of hairs, especially one that naturally curls or has been shaped into a curl.
A stray lock of hair fell across Christopher's face as he read the letter.
lock of hair — countable strand or curl
The baby had soft golden locks that curled around her tiny pink ears.
Roya tucked a loose lock behind her ear before the interview began.
The portrait showed a young woman with a single dark lock resting on her shoulder.
- a lock of hair
- a stray lock
- a loose lock
- golden/dark/curly locks
- tuck a lock behind one's ear
Usage Note
When referring to a single strand or curl, 'a lock' is more formal or literary than 'a strand'. In plural ('locks'), it often blends into the sense 5 meaning of head hair.
5. The hair that grows on a person's head, especially when considered for its amoun
The hair that grows on a person's head, especially when considered for its amount, colour, or general appearance.
The old woman's silver locks shone brightly in the warm afternoon sunlight.
silver/grey/flowing locks — literary for head hair
The fairy tale prince had golden locks that reached down to his shoulders.
Saira shook her dark locks free from the tight bun she had worn all day.
Wind played with her flowing locks as she stood on the cliff edge.
flowing locks — literary/poetic use
- golden/silver/dark/flowing locks
- long/thick/shiny locks
- shake one's locks
- flowing locks
Usage Note
Almost always used in the plural ('locks') and found in literary, poetic, or descriptive writing. In everyday speech, 'hair' is preferred over 'locks'.
6. A way of styling the hair by twisting or matting it into long strands that look
A way of styling the hair by twisting or matting it into long strands that look like ropes; a shortened form of dreadlocks.
Adisa has worn his hair in long locks for over ten years now.
wear + in locks — dreadlocks style
The barber specialized in washing and maintaining locks for her regular clients.
Ilan decorated his locks with small wooden beads and colourful threads.
There are many ways to start natural locks without using wax or gels.
start natural locks
- wear locks
- start locks
- natural locks
- maintain locks
- twist locks
- dreadlocks
the full, more formal term for this hairstyle
- dreads
an even shorter informal abbreviation of dreadlocks
Usage Note
In this sense, 'locks' is an informal shortening of 'dreadlocks'. Used in the plural. The full form 'dreadlocks' is more formal and more widely understood across different English varieties.
Common Mistakes
7. the distance a car's front wheels move to each side when the driver turns the st
the distance a car's front wheels move to each side when the driver turns the steering wheel — for instance, how far they go before they cannot turn any further
Leo turned the steering wheel to full lock to park in a tight space.
collocation: 'full lock' / 'on full lock' when wheels are at their maximum turn
The car's steering lock is wide, making it easy to turn around on narrow roads.
The old van's front wheel lock was so tight that every U-turn took three tries.
Mei turned the steering wheel to full lock to check how far the pickup truck's front wheels could turn.
collocation: 'full lock' — steering wheel at maximum turn angle
- full lock
- on full lock
- steering lock
- front wheel lock
Usage Note
Often used in the phrases 'full lock' or 'on full lock' to describe the steering wheel turned as far as it will go. Without 'steering' or 'front wheel', this sense can be confused with the lock that uses a key.
Common Mistakes
8. a hold used in wrestling or hand-to-hand fighting where you grip part of an oppo
a hold used in wrestling or hand-to-hand fighting where you grip part of an opponent's body firmly, keeping them still and unable to get free
The wrestler held his opponent in a leg lock until he tapped out.
compound nouns: leg lock / arm lock / head lock / neck lock
Andrew escaped from the head lock by twisting his body sharply to the left.
In judo class, Élise learned an arm lock that controls the elbow joint.
The referee stopped the fight when Tunde used a dangerous neck lock.
- arm lock
- leg lock
- head lock
- neck lock
- put someone in a lock
- apply a lock
- escape from a lock
- hold
more general — any controlling grip in wrestling, not necessarily a fixed lock
- grapple
refers to the whole act of wrestling or gripping, not a specific hold
- submission hold
a lock designed to force the opponent to give up, common in MMA context
Usage Note
This sense is most common in combat sports such as wrestling, judo, and mixed martial arts. The specific body part is usually named in a compound: 'arm lock', 'leg lock', 'head lock', 'neck lock'.
Common Mistakes
9. one of the two players in a rugby scrum who stand behind the front row and push
one of the two players in a rugby scrum who stand behind the front row and push forward to win the ball; also used for this playing position itself
Nadia plays lock for the national team and is strong in the scrum.
used without article: 'plays lock for' (position name)
At 198 centimetres tall, Ramón was a natural choice for the lock position.
The team's two locks push together to win possession from the scrum.
Yumi moved from flanker to lock when the starting second-row player got injured.
- play lock
- lock position
- second-row lock
- tighthead lock
- loosehead lock
- second row
the same playing position; 'second row' can refer to the row of the scrum or the players in it
- second-row forward
more descriptive but less common in everyday rugby talk
Usage Note
In rugby union, 'lock' is the standard term for a second-row forward. The position is also called 'second row' informally. When saying which position someone plays, the article is typically dropped: 'He plays lock.'
Common Mistakes
Word family
Synonym discussion
Sense: noun/1
Lock is the most general word for any device that fastens a door, container, or vehicle until a key or code releases it. A padlock (B1) is a specific type of removable lock with a U-shaped shackle, often used on gates, lockers, and chains — it is not built into the door itself like a regular lock. A bolt (B2) is a sliding metal bar pushed across the inside of a door; it has no key and can only be operated from inside, offering extra security rather than everyday access. A latch (B1) is a simple fastening with a spring-loaded bar that catches automatically when you close a door; it can usually be opened from the inside without any tool. In short: you use a lock when you want key-operated security, a padlock when you need a portable lock, a bolt for extra privacy from inside, and a latch for quick but light fastening.
Common collocations
Phrases
- under lock and key — safely locked away
- lock and key — a phrase emphasizing the locking mechanism (e.g., kept under lock and key)
- lock, stock, and barrel — everything; the whole thing
- pick a lock — open a lock without a key, using a tool
- break a lock — force a lock open by damaging it
- a lock on something — total control or surety over something
- lock horns — to argue or fight with someone over something
- put a lock on — to restrict or secure access to something
- turn the key in the lock — the action of locking or unlocking
Etymology
源自中古英語 lok，古英語 loc（閂、栓、圍起來的地方），源自原始日耳曼語 *luk-。最早的「關閉裝置」之意可追溯至 13 世紀。水壩船閘（lock）的用法始於 14 世紀，因閘門關上後形成一段「封閉水道」。角力招式的 lock（如 arm lock）最早見於 16 世紀，形容身體部位像被鎖住一般無法動彈。表示一綹頭髮的 lock 則源自中古英語 locc，來自另一條日耳曼語系字根（比較古諾斯語 lokkr「一綹頭髮」），與「鎖具」的 lock 在歷史上是兩個不同的詞，但在現代英語中拼寫合流成為同形詞。