bowhead vs baleen whale

bowhead and baleen whale both are nouns.

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

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

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

Other hypernyms of bowhead include whalebone whale.

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