bull fiddle vs bass viol

bull fiddle and bass viol both are nouns.

Word	Noun	Adjective	Verb	Adverb
bull fiddle	Yes	No	No	No
bass viol	Yes	No	No	No

As nouns, bull fiddle and bass viol are synonyms defined as:

bull fiddle and bass viol: largest and lowest member of the violin family

Other synonyms of bull fiddle include bass fiddle, contrabass, double bass, string bass.

bull fiddle (noun)	bass viol (noun)
largest and lowest member of the violin family	viol that is the bass member of the viol family with approximately the range of the cello
	largest and lowest member of the violin family