backsets
1backsets — n. current in the opposite direction (especially of water); reversal or backtracking …
2Bored cylindrical lock — A bored cylindrical lock is one in which two holes are bored, perpendicular to one another, into the door. A large hole is bored into the door face and a smaller crossbore hole is bored into the door edge, as opposed to a mortise lock prep cut… …
