lock

The word “lock” means a device that fastens something shut, opened only with a key, code, or similar means. In plain terms, a fastening device (or the act of fastening something), a water-level chamber on a canal, or a strand of hair.

“Lock” is pronounced lok (/lɑk/ in IPA).

Here is “lock” used in a sentence: “She changed the lock on the front door after losing her keys.”

Depending on how it is used, “lock” can be a noun and a verb.

The word “lock” comes from Old English. From Old English loc, "a fastening or enclosure", from a root meaning "to bend or turn".

“Lock” is a fairly common word in modern English, usually learned at around the A2 level.

“Lock” has 4 distinct senses listed in this dictionary. The most common is: a device that fastens something shut, opened only with a key, code, or similar means.

A lock fastens something shut and needs a key, code, or similar means to open, providing security. A latch simply holds a door or gate closed and can usually be opened by hand, without any key. So a latch keeps something shut for convenience, while a lock keeps it secured against unwanted entry.

Common kinds include padlocks, deadbolts, mortice locks, cylinder or Yale-style locks, combination locks that open with a code, and modern electronic or smart locks controlled by keypad, card, or phone. They all share the same job: fastening something shut so it can only be opened by the right key, code, or authorised means.

As a device, a lock has no exact single opposite, but a key is its natural counterpart, since it releases what the lock secures. In terms of action, to unlock or open is the reverse of locking. A lock closes and secures; unlocking frees it so the thing can be opened again.

A padlock on a shed, a deadbolt on a front door, and a combination lock on a locker are all everyday examples. Each is a device that fastens something shut and can only be released with the correct key, code, or similar means, keeping the contents secure.