bass fiddle vs bull fiddle

bass fiddle and bull fiddle both are nouns.

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

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

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

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

bass fiddle (noun)	bull fiddle (noun)
largest and lowest member of the violin family	largest and lowest member of the violin family