1. The hard, white, opaque, fine-grained substance constituting the tusks of the elephant. It is a variety of dentine, characterised by the minuteness and close arrangement of the tubes, as also by their double flexure. It is used in manufacturing articles of ornament or utility.
ivory is the name commercially given not only to the substance constituting the tusks of the elephant, but also to that of the tusks of the hippopotamus and walrus, the hornlike tusk of the narwhal, etc.