柯林斯詞典pectoral fin 1. N either of a pair of fins, situated just behind the head in fishes, that help to control the direction of 胸鰭 返回 pectoral fin劍橋詞典the fin on each side of a fish near the front of its body , used for controlling the direction the fish goes in and for slowing it down 胸鰭（魚(yú)身體前面兩側(cè)的鰭，用于控制和減速） 返回 pectoral fin