n. The hard substance, not unlike bone, of which the teeth of most mammals chiefly consist; specifically, a kind of dentine valuable for industrial purposes, as that derived from the tusks of the elephant, hippopotamus, walrus, narwhal, and some other animals.n. An object made of ivory.n. plural Teeth.Consisting or made of ivory; resembling ivory in color or texture: as, the gown was made of ivory satin.n. A dialectal form of ivy, simulating ivory.n. In mathematics, one of two points on each of two confocal ellipsoids, such that, if the two ellipsoids be referred to their principal axes, the coördinates are in the same proportions as each pair to the axes of the two ellipsoids having the same direction.