Checker (noun)

1. A person who checks or inspects something.
2. A game piece used in various board games, such as checkers and chess.

Origin:

The word 'checker' has its roots in the old french word 'eschequier', meaning a chessboard.

Examples:

1. The checker verified the items on the list one by one.
2. The checkers in the game of checkers are black and red.
3. The checker made sure all the packages were properly labeled.
4. The checker at the security checkpoint searched through the luggage.
5. The checker moved his piece diagonally on the board.