The crossword solution for the term 'Piece in Mr. Potato Head' is EAR, which is a three-letter word. The term refers to one of the pieces that make up the popular children's toy, Mr. Potato Head. The toy consists of a plastic potato body and various accessories such as eyes, ears, noses, and mouths that can be attached to it. The EAR piece is one of the accessories that can be used to create a unique Mr. Potato Head.