/bak"set'/ , n.
1. New England, Southern, and South Midland U.S.
a. a setback; relapse; reverse.
b. an eddy or countercurrent.
2. (on a lock on a door or the like) the horizontal distance between the face through which the bolt passes and the center line of the knob stem or keyhole.
[ 1565-75; BACK 2 + SET ]