biceps brachii vs musculus biceps brachii

biceps brachii and musculus biceps brachii both are nouns.

Word	Noun	Adjective	Verb	Adverb
biceps brachii	Yes	No	No	No
musculus biceps brachii	Yes	No	No	No

As nouns, biceps brachii and musculus biceps brachii are synonyms defined as:

biceps brachii and musculus biceps brachii: a muscle that flexes and supinates the forearm

Other synonyms of biceps brachii include biceps humeri.

biceps brachii (noun)	musculus biceps brachii (noun)
a muscle that flexes and supinates the forearm	a muscle that flexes and supinates the forearm