bluefin vs tuna

bluefin and tuna both are nouns.

Word	Noun	Adjective	Verb	Adverb
bluefin	Yes	No	No	No
tuna	Yes	No	No	No

As nouns, tuna is a hypernym of bluefin; that is, tuna is a word with a broader meaning than bluefin:

bluefin: largest tuna; to 1500 pounds; of mostly temperate seas: feed in polar regions but breed in tropics
tuna: any very large marine food and game fish of the genus Thunnus; related to mackerel; chiefly of warm waters

Other hypernyms of bluefin include tunny.

As nouns, tuna is a hypernym of bluefin; that is, tuna is a word with a broader meaning than bluefin:

bluefin: flesh of very large tuna
tuna: important warm-water fatty fish of the genus Thunnus of the family Scombridae; usually served as steaks

Other hypernyms of bluefin include tuna fish, tunny.

bluefin (noun)	tuna (noun)
largest tuna; to 1500 pounds; of mostly temperate seas: feed in polar regions but breed in tropics	any very large marine food and game fish of the genus Thunnus; related to mackerel; chiefly of warm waters
flesh of very large tuna	New Zealand eel
	important warm-water fatty fish of the genus Thunnus of the family Scombridae; usually served as steaks
	tropical American prickly pear of Jamaica