a bowed musical instrument, differing from the violin in having deeper ribs, sloping shoulders, a greater number of strings, usually six, and frets: common in the 16th and 17th centuries in various sizes from the treble viol to the bass viol.
Origin of viol
1475–85; < Middle Frenchviole (akin to Old Frenchviel(l)e > earlier Englishviele) < Old Provençalviola, derivative of violar to play the viola1 (perhaps imitative)
any of a family of stringed musical instruments that preceded the violin family, consisting of a fretted fingerboard, a body rather like that of a violin but having a flat back and six strings, played with a curved bow. They are held between the knees when played and have a quiet yet penetrating tone; they were much played, esp in consorts, in the 16th and 17th centuries
Word Origin for viol
C15: from Old French viole, from Old Provençal viola; see viola1