MORTISE

mortice [noun] [C] [specialized] - a rectangular hole in a piece of wood, stone, etc. into which another piece is fixed, so that they form a jointThe structure was made in the traditional manner, using mortice and tenon joints secured with oak pegs.(UK) A mortise lock (US dead bolt, ANZ deadlock) is a lock that is enclosed within the edge of a door, so that it cannot be seen or removed when the door is closed.After the robbery, the police advised me to have a mortice lock fitted on the back door.