A four-stringed instrument is a type of musical instrument that has four strings. The three crossword solutions for this term are uke (3 letters), BASS (4 letters), VIOLA (5 letters), and ukulele (7 letters). A uke is a small guitar-like instrument, a BASS is a stringed instrument that produces a low-pitched sound, a VIOLA is a bowed string instrument, and a ukulele is a small four-stringed instrument that originated in Hawaii.