deadbolt

Plural: deadbolts

Noun

• the part of a lock that is engaged or withdrawn with a key
• The part of the lock which is moved when the key is engaged.
• A kind of lock in which the bolt (moving portion) is held in position by the cylinder rather than by a spring and so cannot be retracted except by turning the cylinder.

Verb

• To fasten or secure with a deadbolt.

Synonyms

bolt, deadlock