The term 'HALF OF THE CHESS PIECES' can be solved by the word 'PAWNS', which is a five-letter word. PAWNS are the most numerous pieces in a game of chess, making up half of the total pieces on the board. They are the weakest pieces and can only move forward one square at a time, but they can capture pieces diagonally. PAWNS can also be promoted to a higher-ranking piece if they reach the opposite side of the board.