Possible Definitions:
1. Checker (v. t.) One who checks.
2. Checker (n.) To mark with small squares like a checkerboard, as by crossing stripes of different colors.
3. Checker (n.) To variegate or diversify with different qualities, colors, scenes, or events; esp., to subject to frequent alternations of prosperity and adversity.
4. Checker (v. t.) A piece in the game of draughts or checkers.
5. Checker (v. t.) A pattern in checks; a single check.
6. Checker (v. t.) Checkerwork.