horse mackerel vs bluefin

horse mackerel and bluefin both are nouns.

Word	Noun	Adjective	Verb	Adverb
horse mackerel	Yes	No	No	No
bluefin	Yes	No	No	No

As nouns, horse mackerel and bluefin are synonyms defined as:

horse mackerel and bluefin: largest tuna; to 1500 pounds; of mostly temperate seas: feed in polar regions but breed in tropics

Other synonyms of horse mackerel include bluefin tuna, Thunnus thynnus.

horse mackerel (noun)	bluefin (noun)
a California food fish	largest tuna; to 1500 pounds; of mostly temperate seas: feed in polar regions but breed in tropics
large elongated compressed food fish of the Atlantic waters of Europe	flesh of very large tuna
largest tuna; to 1500 pounds; of mostly temperate seas: feed in polar regions but breed in tropics