lock

Something used for fastening, which can only be opened with a key or combination.

• "Give me the key," said my mother; and though the lock was very stiff, she had turned it and thrown back the lid in a twinkling.

A mutex or other token restricting access to a resource.broadly

• [T]he application must first acquire a lock on a file or a portion of a file before reading data and modifying it.

A segment of a canal or other navigable waterway enclosed by gates, used for raising and lowering boats between levels.

• Here the canal came to a check, ending abruptly with a large lock.

The firing mechanism in a gun.

• "I never saw such a gun in my life," replied poor Winkle, looking at the lock, as if that would do any good.

Complete control over a situation.

• Even though he had not yet done so, Jack felt he had a lock on the game.

Something sure to be a success.

• Brian thinks she's a lock to get a scholarship somewhere.

Synonym of Dutch book.

A player in the scrum behind the front row, usually the tallest members of the team.

• Ashton only had to wait three minutes for his second try, lock Louis Deacon setting it up with a rollocking line-break, before Romania got on the scoreboard courtesy of a penalty from fly-half Marin Danut Dumbrava.

A fastening together or interlacing; a closing of one thing upon another; a state of being fixed or immovable.

• [O]n may of his lecture days I have seen all Albemarle Street closed by a "lock" of carriages, filled with women of distinction, until the servants of the Institution or their own footmen advanced to the carriage-doors with the intelligence

A place impossible to get out of, as by a lock.

• Sergestus, eager with his beak to press / Betwixt the rival galley and the rock, / Shuts up the unwieldy Centaur in the lock

To become fastened in place.intransitive

• If you put the brakes on too hard, the wheels will lock.

To fasten with a lock.transitive

• Remember to lock the door when you leave.

To be capable of becoming fastened in place.intransitive

• This door locks with a key.

To intertwine or dovetail.transitive

• with his hands locked behind his back
• We locked arms and stepped out into the night.

To freeze one's body or a part thereof in place.intransitive

• a pop and lock routine

To furnish (a canal) with locks.

To raise or lower (a boat) in a lock.

To seize (e.g. the sword arm of an antagonist) by turning one's left arm around it, to disarm them.

To modify (a thread) so that users cannot make new posts in it.Internettransitive

To prevent a page from being edited by other users.Internettransitive

• Frequently-vandalized pages are generally locked to prevent further damage.

A tuft or length of hair, wool, etc.

• If I consent to burn them, will you promise faithfully neither to send nor receive a letter again, nor a book (for I perceive you have sent him books), nor locks of hair, nor rings, nor playthings?

A small quantity of straw etc.

A quantity of meal, the perquisite of a mill-servant.historical

A single dreadlock.

To form a dreadlock.