deadbolt
/ˈdɛdˌboʊlt/
noun
- A type of lock that has a bolt that slides into the door frame and cannot be moved by a spring, providing extra security.
- She installed a deadbolt on the front door for added safety.
- The landlord requires all apartments to have a deadbolt on the main entrance.
- He turned the key in the deadbolt and heard it click into place.