bowhead vs bowhead whale

bowhead and bowhead whale both are nouns.

Word	Noun	Adjective	Verb	Adverb
bowhead	Yes	No	No	No
bowhead whale	Yes	No	No	No

As nouns, bowhead and bowhead whale are synonyms defined as:

Other synonyms of bowhead include Balaena mysticetus, Greenland whale.

bowhead (noun)	bowhead whale (noun)
large-mouthed Arctic whale	large-mouthed Arctic whale