bass viol

[beys] /beɪs/
noun
1.
viola da gamba.
Origin
1580-90
British Dictionary definitions for bass viols

bass viol

/beɪs/
noun
1.
another name for viola da gamba
2.
(US) a less common name for double bass (sense 1)
bass viols in Culture
bass viol [(veye-uhl)]

The largest and lowest-pitched instrument of the strings, also called a bass fiddle or double bass. The player must stand or sit on a tall stool to play it.