2. a. One that is supreme or preeminent in a particular group, category, or sphere: "In many countries, soccer is the king of sports" (Cameron W. Barr).
b. A man chosen as the winner of a contest or the honorary head of an event: a homecoming king.
3. Games a. Abbr. K A playing card bearing the figure of a king, ranking above a queen.
b. Abbr. K The principal chess piece, which can move one square in any direction and must be protected against checkmate.
c. A piece in checkers that has been moved to the last row on the opponent's side of the board and been crowned, thus becoming free to move both forward and backward.