mollusk

n. 软体动物

An animal, such as an insect or a mollusk, that lacks a backbone or spinal column.

无脊椎动物缺少脊骨或脊柱的动物，例如昆虫或软体动物

The pearly internal layer of certain mollusk shells, used to make decorative objects.

珠母层某些软体动物壳内似珍珠的层，用来做装饰物