finback vs fin whale

finback and fin whale both are nouns.

Word	Noun	Adjective	Verb	Adverb
finback	Yes	No	No	No
fin whale	Yes	No	No	No

As nouns, finback and fin whale are synonyms defined as:

finback and fin whale: large flat-headed whalebone whale having deep furrows along the throat; of Atlantic and Pacific

Other synonyms of finback include Balaenoptera physalus, common rorqual, finback whale.

finback (noun)	fin whale (noun)
large flat-headed whalebone whale having deep furrows along the throat; of Atlantic and Pacific	large flat-headed whalebone whale having deep furrows along the throat; of Atlantic and Pacific