The term 'VIOLIN's Kin' refers to two string instruments related to the VIOLIN: the CELLO (5 letters) and the rebec (5 letters). The CELLO is a larger, lower-pitched instrument that is held between the legs of the player and played with a bow. It is often used as a solo instrument in classical music. The rebec is an ancient bowed string instrument that was popular in Europe during the Middle Ages and Renaissance. It is smaller than the CELLO and has a higher pitch. Both instruments are related to the VIOLIN and are commonly used in orchestras and chamber music.