ivory The fine-grained creamy-white dentine forming the tusks of elephants, and the teeth or tusks of certain other large animals such as the walrus; it has long been esteemed for a wide variety of ornamental articles(细粒度乳白色牙本质形成的大象的长牙,以及其他一些大型动物的牙齿或长牙,如海象象牙;一直以可成为各种装饰物品而著称。)