Lock, in its primary sense, is any thing that fastens; but we now appropriate the word to an instrument composed of a spring, wards, and a bolt of iron or steel, used to fasten doors, chests and the like. The bolt is moved by a key.

The part of a musket or fowling-piece or other fire-arm, which contains the pan, trigger.

The barrier or works of a canal, which confine the water, consisting of a dam, banks or walls, with two gates or pairs of gates, which may be opened or shut at pleasure.

A grapple in wrestling.

Any inclosure.

A tuft of hair; a plexus of wool, hay or other like substance; a flock; a ringlet of hair. A lock of hair will draw more than a cable rope. Lock of water, is the measure equal to the contents of the chamber of the locks by which the consumption of water on a canal is estimated.

To fasten with a particular instrument; as, to lock a door; to lock a trunk.

To shut up or confine, as with a lock; as, to be locked in a prison. Lock the secret in your breast.

To close fast. The frost locks up our rivers.

To embrace closely; as, to lock one in the arms.

To furnish with locks, as a canal.

To confine; to restrain. Our shipping was locked up by the embargo.

In fencing, to seize the sword-arm of an antagonist, by turning the left arm around it, after closing the parade, shell to shell, in order to disarm him.

To become fast. The door locks close.

To unite closely by mutual insertion; as, they lock into each other.