A device operated by a key, combination, or keycard and used, as on a door, for holding, closing, or securing.
A section of a waterway, such as a canal, closed off with gates, in which vessels in transit are raised or lowered by raising or lowering the water level of that section.
A mechanism in a firearm for exploding the charge.
An interlocking or entanglement of elements or parts.
Sports A hold in wrestling or self-defense that is secured on a part of an opponent's body.
A secure hold; control: The distributor has a lock on most of the market.
A sure thing; a certainty: His promotion is a lock.
To fasten the lock of: close and lock a drawer.
To shut or make secure with or as if with locks: locked the house.
To confine or exclude by or as if by means of a lock: locked the dog in for the night; locked the criminal up in a cell.
To fix in place so that movement or escape is impossible; hold fast: The ship was locked in the ice through the winter. She felt that she had become locked into a binding agreement.
To sight and follow (a moving target) automatically: locked the enemy fighter in the gun sights.
To aim (a weapon or other device) at a moving target so as to follow it automatically: "The pilot had locked his targeting radar on the slow-moving frigate” ( Ed Magnuson).
To engage and interlock securely so as to be immobile.
To clasp or link firmly; intertwine: locked arms and walked away.
To bind in close struggle or battle: The two dogs were locked in combat.
To equip (a waterway) with locks.
To pass (a vessel) through a lock.
Printing To secure (letterpress type) in a chase or press bed by tightening the quoins.
Printing To fasten (a curved plate) to the cylinder of a rotary press.
To invest (funds) in such a way that they cannot easily be converted into cash.
Computer Science To end the processing of (a magnetic tape or disk) in such a way as to deny access to its contents.
Computer Science To protect (a file) from changes or deletion.
To become fastened by or as if by means of a lock: The door locks automatically when shut.