shell /ʃel/ n. ［c］1. (贝)壳，外壳：the shell of a snail(crab, tortoise) 蜗牛（螃蟹，龟）壳；cast the shell 脱壳；the shell of the earth 地壳 2. 炮弹：a tear shell 催泪弹；fire shells at the enemy 对准敌人开炮