One who checks or verifies something.

One who makes a check mark.

The clerk who tallies cost of purchases and accepts payment.

“There was a long line at the grocery store because the checker was so slow.”

A playing piece in the game of checkers (British: draughts).

A pattern of alternating colours as on a chessboard.

The fruit of the wild service tree or chequer tree, Photinia villosa, syn. Sorbus terminalis