The term CRATE PIECE can be solved by the four-letter word SLAT. A SLAT is a thin, narrow strip of wood or metal used to form part of a larger structure, such as a crate. Slats are often used to make up the sides and bottom of a crate, providing support and stability. They are also used to create shelves, benches, and other furniture. Slats are typically made from wood, metal, or plastic, and can be found in a variety of sizes and shapes.