ivory

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A hard, smooth, yellowish-white substance composed primarily of dentin that forms the tusks of the elephant.
2. n. A similar substance forming the tusks or teeth of certain other mammals, such as the walrus.
3. n. A tusk, especially an elephant's tusk.
4. n. An article made of ivory.
5. n. A substance resembling ivory.
6. n. A pale or grayish yellow to yellowish white.
7. n. Music Piano keys.
8. n. Games Dice.
9. n. Slang The teeth.
10. adj. Composed or constructed of ivory.
11. adj. Of a pale or grayish yellow to yellowish white.

Century Dictionary and Cyclopedia

1. 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. Ivory is simply dentine or tooth-substance of exceptional hardness, toughness, and elasticity, due to the fineness and regularity of the dentinal tubules which radiate from the axial pulpcavity to the periphery of the tooth. The most valuable ivory is that obtained from elephants' tusks, in which the tubules make many strong bends at regular intervals, resulting in a pattern peculiar to the proboscideau mammals. Iu its natural state the ivory of a tusk is coated with cement; and besides the fine angular radiating lines, it shows on cross-section a series of contour-lines concentric with the axis of the tooth, arranged about a central grayish spot which represents the calcified pulp. The appearance of these contour-lines is due to the regular arrangement of minute spaces called interglobular. Ivory in comparison with ordinary dentine is specially rich in organic matter, containing 40 per cent, or more. Tusks of extinct mammoths, furnishing fossil ivory, have been found 12 feet long and of 200 pounds weight. Those of the African elephant, furnishing the best ivory, as well as by far the greater portion of the ivory used in the arts, sometimes reach a length of 9 feet and a weight of 160 pounds. Those of the Indian elephant are never so large as this; aud in either case tusks average much smaller, probably under 50 pounds. Elephants' tusks are incisors, but the large teeth of the hippopotamus and walrus which furnish ivory are canines. A substance which sometimes passes for ivory, but is really bone, is derived from the very hard or petrosal parts of the ear-bones of whales.
2. n. An object made of ivory.
3. n. plural Teeth.
4. Consisting or made of ivory; resembling ivory in color or texture: as, the gown was made of ivory satin.
5. n. A dialectal form of ivy, simulating ivory.
6. 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.

Wiktionary

1. n. The hard white form of dentine which forms the tusks of elephants, walruses and other animals.
2. n. A creamy white colour, the colour of ivory.
3. n. Something made from or resembling ivory.
4. n. The teeth.
5. n. The keys of a piano.
6. adj. Made of ivory.
7. adj. Resembling or having the colour of ivory.

GNU Webster's 1913

1. n. The hard, white, opaque, fine-grained substance constituting the tusks of the elephant. It is a variety of dentine, characterized 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.
2. n. The tusks themselves of the elephant, etc.
3. n. Any carving executed in ivory.
4. n. Teeth.

WordNet 3.0

1. n. a shade of white the color of bleached bones
2. n. a hard smooth ivory colored dentine that makes up most of the tusks of elephants and walruses