trigeminus vs nervus trigeminus

trigeminus and nervus trigeminus both are nouns.

Word	Noun	Adjective	Verb	Adverb
trigeminus	Yes	No	No	No
nervus trigeminus	Yes	No	No	No

As nouns, trigeminus and nervus trigeminus are synonyms defined as:

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

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

trigeminus (noun)	nervus trigeminus (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