bluefin vs horse mackerel

bluefin and horse mackerel both are nouns.

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

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

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

Other synonyms of bluefin include bluefin tuna, Thunnus thynnus.

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