The crossword solution for the term 'Queen or King, e.g.' is PIECE, which is a 5-letter word. PIECE is a term used to refer to a monarch, such as a queen or king, in a game of chess. In chess, the pieces are the various types of pieces that can be moved around the board, including the king, queen, rooks, bishops, knights, and pawns. Each PIECE has its own unique movement and purpose, and the goal of the game is to use these pieces to checkmate the opponent's king.