From Longman Dictionary of Contemporary Englishdeadboltdead‧bolt /ˈdedbəʊlt $ -boʊlt/ noun [countable] DHHa strong lock often used on doors
Examples from the Corpus
deadbolt• Close the door and mark the area for the deadbolt.• Open the door; hold the striker plate against the door frame in line with the deadbolt mark, and pencil in the outline. 