Noun
The largest instrument of the bass-viol kind, having strings tuned an octave below those of the violoncello; the contrabasso; -- called also double bass.
Source: Webster's dictionaryAlthough most diminutions are written for organ, string instruments or cornett, Suzanne is "per violone over Trombone alla bastarda". Source: Internet
He says that "most likely its first general shape was that of a violone, the largest member of the viol family. Source: Internet
Contained in his Concerti ecclesiastici (Milan 1610) is his brother Andrea's Capriccio 'for cornett and trombone or violin and violone'. Source: Internet
The bass violin was actually often referred to as a "violone," or "large viola," as were the viols of the same period. Source: Internet
This 1640 painting shows a violone being played. Source: Internet