noun.
The modern form of the medieval viola da gamba.
noun.
In organ-building, a pedal stop of eight-feet tone, having metal pipes of narrow scale and a very string-like quality.
the GNU version of the Collaborative International Dictionary of English
noun.
A stringed instrument of music; a bass viol of four strings, or a bass violin with long, large strings, giving sounds an octave lower than the viola, or tenor or alto violin.