The term 'String Instrument Ancient' can be summarized by the crossword solution 'LYRE' (4 letters). The LYRE is an ancient string instrument that was popular in Ancient Greece and Mesopotamia. It is a harp-like instrument with strings stretched across a frame, usually made of wood. The LYRE was used for accompaniment in religious ceremonies, as well as for entertainment purposes. It is still used today in some parts of the world.