trigeminus vs trigeminal nerve

trigeminus and trigeminal nerve both are nouns.

Word	Noun	Adjective	Verb	Adverb
trigeminus	Yes	No	No	No
trigeminal nerve	Yes	No	No	No

As nouns, trigeminus and trigeminal nerve are synonyms defined as:

trigeminus and trigeminal nerve: the main sensory nerve of the face and motor nerve for the muscles of mastication

Other synonyms of trigeminus include fifth cranial nerve, nervus trigeminus, trigeminal.

trigeminus (noun)	trigeminal nerve (noun)
the main sensory nerve of the face and motor nerve for the muscles of mastication	the main sensory nerve of the face and motor nerve for the muscles of mastication