bowhead vs whalebone whale

bowhead and whalebone whale both are nouns.

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

As nouns, whalebone whale is a hypernym of bowhead; that is, whalebone whale is a word with a broader meaning than bowhead:

bowhead: large-mouthed Arctic whale
whalebone whale: whale with plates of whalebone along the upper jaw for filtering plankton from the water

Other hypernyms of bowhead include baleen whale.

bowhead (noun)	whalebone whale (noun)
large-mouthed Arctic whale	whale with plates of whalebone along the upper jaw for filtering plankton from the water