1N-COUNT 鳍 A fish's fins are the flat objects which stick out of its body and help it to swim and keep its balance. 鳍
2N-COUNT 鳍状物;(飞机等的)垂直安定面;(火箭、炸弹等的)尾翼 A fin on something such as an aeroplane, rocket, or bomb is a flat part which sticks out and which is intended to help control its movement. 鳍状物;(飞机等的)垂直安定面;(火箭、炸弹等的)尾翼