narwhale vs Monodon monoceros

narwhale and Monodon monoceros both are nouns.

Word	Noun	Adjective	Verb	Adverb
narwhale	Yes	No	No	No
Monodon monoceros	Yes	No	No	No

As nouns, narwhale and Monodon monoceros are synonyms defined as:

narwhale and Monodon monoceros: small Arctic whale the male having a long spiral ivory tusk

Other synonyms of narwhale include narwal, narwhal.

narwhale (noun)	Monodon monoceros (noun)
small Arctic whale the male having a long spiral ivory tusk	small Arctic whale the male having a long spiral ivory tusk