a large type of tuna (= a fish that lives in warm seas) that has some yellow fins (= thin vertical parts sticking out of it body that help balance and movement), or the flesh of this fish eaten as food

He sent a photograph of himself holding a yellowfin tuna. 他发了一张自己抱着条黄鳍金枪鱼的照片。

The brunch menu includes seared yellowfin tuna. 早午餐菜单包括烤黄鳍金枪鱼。