/skrooh"bawl'/ , n.
1. Slang. an eccentric or whimsically eccentric person; a nut.
2. Baseball. a pitched ball that curves toward the side of the plate from which it was thrown.
adj.
3. Slang. eccentric or whimsically eccentric: What a screwball idea!
[ 1865-70; 1935-40 for def. 2; SCREW + BALL 1 ]