BLUEFIN
bluefin, bluefin tuna, horse mackerel, Thunnus thynnus
(noun) largest tuna; to 1500 pounds; of mostly temperate seas: feed in polar regions but breed in tropics
bluefin, bluefin tuna
(noun) flesh of very large tuna
Source: WordNet® 3.1
Etymology
Noun
bluefin (plural bluefins)
bluefin tuna, any of a number of types of tuna characterised by their blue fins.
Source: Wiktionary
Blue"fin`, n. (Zoöl.)
Definition: A species of whitefish (Coregonus nigripinnis) found in Lake
Michigan.
Source: Webster’s Unabridged Dictionary 1913 Edition