deadbolt

/ˈdɛdˈboʊlt/

/ˈdɛdbəʊlt/

A deadbolt is a type of lock that you need a key to open. It's very common to have a deadbolt on an apartment door or the front door of a house.

When you turn a key in the lock of a deadbolt, the bolt slides in or out of an opening in the door jamb. Deadbolts are considered to be secure locks that are difficult to open without a key, especially when compared to a spring-loaded lock, the kind you see in the center of a doorknob. While spring latches can be pushed back manually, deadbolts can't — which is why they're called deadbolts. They're dead, or unmovable.

Definitions of deadbolt

1. noun

   the part of a lock that is engaged or withdrawn with a key
   synonyms: bolt

   types:

   safety bolt, safety lock

   a bolt that cannot be moved from outside the door or gate

   type of:

   bar

   a rigid piece of metal or wood; usually used as a fastening or obstruction or weapon