General English

  • noun a part of a door or container such as a box, used for fastening it so that you can only open it with a key
  • verb to close a door or a container such as a box, using a key
  • verb to fix something or to become fixed in a certain position

General Science

  • verb to secure a door by turning a key in the lock
  • verb to block or stop the movement of something


  • noun a device operated by a key for securing a door, etc.
  • verb to be in or to move into a secure position
  • verb to block or prevent moving

Cars & Driving

  • noun a device for closing something with a key to prevent unauthorized entry
  • noun the amount by which the wheels of a vehicle are able to turn


  • verb to prevent access to a system or file


  • To secure, hold, stabilize, or set.
  • To deny access, prevent operation, or preclude any changes or deletion. Also, a setting, device, or feature which puts such restrictions into effect, or which helps implement them.

Information & Library Science

  • verb to fasten something to prevent access

Media Studies

  • verb to fix metal type in a printing press


  • noun a mechanism for securing one object to another (which usually requires a key to open it)
  • noun an enclosed stretch of a canal or river, in which the water level can be raised or lowered by the use of gates


  • noun a certainty, usually heard in the teenagers’ phrase ‘it’s a lock’. This sense of the word is an adaptation of the colloquial phrase to ‘have (the situation) all locked up’.
  • noun a person of Polish origin or descent. The racist term heard in the US is supposedly a corruption of polack.


  • noun a device for closing a door or box so that it can be opened only with a key
  • noun a section of a canal or river with barriers which can be opened or closed to control the flow of water, so allowing boats to move up or down to different levels

Origin & History of “lock”

English has two words lock. The one meaning ‘fastening mechanism’ goes back ultimately to a prehistoric Germanic *luk-or *lūk-, denoting ‘close’, which also produced German loch ‘hole’ and Swedish lock ‘lid’. Closely related are locker (15th c.), etymologically a ‘box with a lock’, and locket (14th c.), which was acquired from Old French locquet, a diminutive form of loc (which itself was a borrowing from Germanic *luk-).

Lock ‘piece of hair’ goes back to a prehistoric Indo-European *lug-, which denoted ‘bending’. Its Germanic relatives include German locke, Dutch and Danish lok, and Swedish lock.