The term 'Piano Key Wood' refers to the material used to make the keys of a piano. The two crossword solutions for this term are 'EBONY' (5 letters) and 'EBON' (4 letters). EBONY is a dense black wood, most commonly sourced from the Diospyros genus of trees, which is often used in the construction of musical instruments such as pianos. EBON is a variant spelling of EBONY, and is also used to refer to the same type of wood.