# lock

/ˈɫɑk/ (US) · /lˈɒk/ (UK)

Source: https://englishreference.com/word/lock
Updated: 2026-06-19

## Senses

### 1. fastening device

noun · CEFR A2

a device that keeps a door, window, or container closed and usually requires a key to open.

For teachers: a mechanism for securing a door, lid, or moving part, typically operated by a key, combination, or electronic signal.

- He put the key in the lock and turned it slowly to open the front door.
- The locksmith recommended a high-security deadbolt lock to ensure the warehouse remained protected against forced entry during the night.

### 2. hair

noun · CEFR B2 · Literary

a small group of hairs that grow or hang together.

For teachers: a tuft, tress, or ringlet of hair, wool, or similar fibre.

- She brushed a stray lock of hair away from her eyes.
- The locket contained a single lock of golden hair, preserved perfectly as a memento of a childhood long since passed.

### 3. waterway

noun · CEFR B2

a section of a canal with gates used to raise or lower boats to different water levels.

For teachers: an enclosure in a canal or river with gates at each end, used for raising or lowering vessels between stretches of different water levels.

- The boat waited for the water to rise in the lock before moving to the next part of the canal.
- Navigating the series of narrow locks required precise steering to avoid damaging the hull against the ancient stone walls of the canal.

### 4. a sure thing

noun · CEFR C1 · Informal · American English

something that is certain to happen or be successful.

For teachers: a person or thing considered a certainty for success or a specific outcome.

- With her experience, she is a lock for the promotion.
- After the incumbent's scandal, the opposition candidate was considered a lock for the seat, though the final polling suggested a tighter race.

### 5. to fasten

verb · CEFR A2

to close something with a lock so that it cannot be opened without a key.

For teachers: to secure a door, container, or vehicle by means of a lock; to make something immovable.

- Don't forget to lock the car when you go into the shop.
- The protocol requires the last employee on site to lock all external exits and activate the alarm system before departing.

### 6. to freeze in place

verb · CEFR B2

to become fixed in one position and unable to move.

For teachers: to become fixed, motionless, or jammed in a particular position.

- The wheels of the old bicycle started to lock because of the rust.
- The cold weather caused the steering mechanism to lock, forcing the driver to pull over immediately for safety.

### 7. computing/internet

verb · CEFR B2 · Technical

to stop people from changing a file or posting on a website.

For teachers: to restrict access to a digital resource, such as a database record or a forum thread, to prevent concurrent modification or further input.

- The moderator had to lock the discussion because people were being rude.
- The system will automatically lock the file while it is being edited to prevent data corruption from multiple users.

## Examples

- The front door has a strong lock.
- He turned the key in the lock and pushed the heavy oak door open.
- The antique chest was secured with an intricate brass lock that had resisted all attempts to be picked over the centuries.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.