Terminology
When use of the word "violone" began in the early sixteenth century, "viola" simply meant a bowed, stringed instrument, and did not specify viol or violin. Historically "violone" has referred to any number of large fiddles, regardless of family.
The term violone is sometimes used to refer to the modern double bass, but most often nowadays implies a period instrument. As a period instrument, it can refer to any of the different types that are described, above.
"Violone" is also the name given to a non-imitative string-tone pipe organ stop, constructed of either metal or wood, and found in the pedal division at 16' pitch (one octave below written pitch), or, more rarely, 32' (2 octaves below written pitch).
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