Source : Webster's Revised Unabridged Dictionary (1913)

   1. 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.

   Note: 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.

   2. The tusks themselves of the elephant, etc.

   3. Any carving executed in ivory. --Mollett.

   4. pl. Teeth; as, to show one's ivories. [Slang]

   {Ivory black}. See under {Black}, n.

   {Ivory gull} (Zo["o]l.), a white Arctic gull ({Larus
      eburneus}).

   {Ivory nut} (Bot.), the nut of a species of palm, the
      {Phytephas macroarpa}, often as large as a hen's egg. When
      young the seed contains a fluid, which gradually hardness
      into a whitish, close-grained, albuminous substance,
      resembling the finest ivory in texture and color, whence
      it is called {vegetable ivory}. It is wrought into various
      articles, as buttons, chessmen, etc. The palm is found in
      New Grenada. A smaller kind is the fruit of the {Phytephas
      microarpa}. The nuts are known in commerce as Corosso
      nuts.

   {Ivory palm} (Bot.), the palm tree which produces ivory nuts.
      

   {Ivory shell} (Zo["o]l.), any species of {Eburna}, a genus of
      marine gastropod shells, having a smooth surface, usually
      white with red or brown spots.

   {Vegetable ivory}, the meat of the ivory nut. See {Ivory nut}
      (above).

Vegetable \Veg`e*ta*ble\, a. [F. v['e]g['e]table growing,
   capable of growing, formerly also, as a noun, a vegetable,
   from L. vegetabilis enlivening, from vegetare to enliven,
   invigorate, quicken, vegetus enlivened, vigorous, active,
   vegere to quicken, arouse, to be lively, akin to vigere to be
   lively, to thrive, vigil watchful, awake, and probably to E.
   wake, v. See {Vigil}, {Wake}, v.]
   1. Of or pertaining to plants; having the nature of, or
      produced by, plants; as, a vegetable nature; vegetable
      growths, juices, etc.

            Blooming ambrosial fruit Of vegetable gold.
                                                  --Milton.

   2. Consisting of, or comprising, plants; as, the vegetable
      kingdom.

   {Vegetable alkali} (Chem.), an alkaloid.

   {Vegetable brimstone}. (Bot.) See {Vegetable sulphur}, below.
      

   {Vegetable butter} (Bot.), a name of several kinds of
      concrete vegetable oil; as that produced by the Indian
      butter tree, the African shea tree, and the {Pentadesma
      butyracea}, a tree of the order {Guttifer[ae]}, also
      African. Still another kind is pressed from the seeds of
      cocoa ({Theobroma}).

   {Vegetable flannel}, a textile material, manufactured in
      Germany from pine-needle wool, a down or fiber obtained
      from the leaves of the {Pinus sylvestris}.

   {Vegetable ivory}. See {Ivory nut}, under {Ivory}.

   {Vegetable jelly}. See {Pectin}.

   {Vegetable kingdom}. (Nat. Hist.) See the last Phrase, below.
      

   {Vegetable leather}.
      (a) (Bot.) A shrubby West Indian spurge ({Euphorbia
          punicea}), with leathery foliage and crimson bracts.
      (b) See {Vegetable leather}, under {Leather}.

   {Vegetable marrow} (Bot.), an egg-shaped gourd, commonly
      eight to ten inches long. It is noted for the very tender
      quality of its flesh, and is a favorite culinary vegetable
      in England. It has been said to be of Persian origin, but
      is now thought to have been derived from a form of the
      American pumpkin.

   {Vegetable oyster} (Bot.), the oyster plant. See under
      {Oyster}.

   {Vegetable parchment}, papyrine.

   {Vegetable sheep} (Bot.), a white woolly plant ({Raoulia
      eximia}) of New Zealand, which grows in the form of large
      fleecy cushions on the mountains.

   {Vegetable silk}, a cottonlike, fibrous material obtained
      from the coating of the seeds of a Brazilian tree
      ({Chorisia speciosa}). It us used for various purposes, as
      for stuffing, and the like, but is incapable of being spun
      on account of a want of cohesion among the fibers.

   {Vegetable sponge}. See 1st {Loof}.

   {Vegetable sulphur}, the fine highly inflammable spores of
      the club moss ({Lycopodium clavatum}); witch.

   {Vegetable tallow}, a substance resembling tallow, obtained
      from various plants; as, {Chinese vegetable tallow},
      obtained from the seeds of the tallow tree. {Indian
      vegetable tallow} is a name sometimes given to piney
      tallow.

   {Vegetable wax}, a waxy excretion on the leaves or fruits of
      certain plants, as the bayberry.

Source : WordNet®

vegetable ivory
     n : nutlike seed of a South American palm; the hard white shell
         takes a high polish and is used for e.g. buttons [syn: {ivory
         nut}, {apple nut}]