1 one of the parts of a fish that it uses for swimming 鳍 ☞picture on page C1 见C1页插图

2 a flat, thin part that sticks out of an aircraft, a vehicle, etc to improve its balance and movement through the air or water （飞机的）垂直尾翼；（船的）鳍板，水平舵；（车辆的）鳍状稳定板