Webster's Revised Unabridged Dictionary · 1913

Viol

Viol , noun

[French viole; compare Pr. viola, viula, Sp., Portuguese, & Italian viola, Late Latin vitula; of uncertain origin; perhaps from Latin vitulari to celebrate a festival, keep holiday, be joyful, perhaps originally, to sacrifice a calf (vitulus; compare Veal). Compare Fiddle, Vielle, 2d Viola, Violin.]

1.
(Music) A stringed musical instrument formerly in use, of the same form as the violin, but larger, and having six strings, to be struck with a bow, and the neck furnished with frets for stopping the strings.
Me softer airs befit, and softer strings Of lute, or viol still, more apt for mournful things. — Milton

The name is now applied as a general term to designate instruments of the violin kind, as tenor viol, bass viol, etc.

2.
(Nautical) A large rope sometimes used in weighing anchor. — Totten