lock

a fastener fitted to a door or drawer to keep it firmly closed

a strand or cluster of hair

a mechanism that detonates the charge of a gun

enclosure consisting of a section of canal that can be closed to control the water level; used to raise or lower vessels that pass through it

a restraint incorporated into the ignition switch to prevent the use of a vehicle by persons who do not have the key

any wrestling hold in which some part of the opponent's body is twisted or pressured

fasten with a lock

“lock the bike to the fence”

keep engaged

“engaged the gears”

become rigid or immoveable

“The therapist noticed that the patient's knees tended to lock in this exercise”

hold in a locking position

“He locked his hands around her neck”

become engaged or intermeshed with one another

“They were locked in embrace”

hold fast (in a certain state)

“He was locked in a laughing fit”