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).

Black \Black\, n.
   1. That which is destitute of light or whiteness; the darkest
      color, or rather a destitution of all color; as, a cloth
      has a good black.

            Black is the badge of hell, The hue of dungeons, and
            the suit of night.                    --Shak.

   2. A black pigment or dye.

   3. A negro; a person whose skin is of a black color, or
      shaded with black; esp. a member or descendant of certain
      African races.

   4. A black garment or dress; as, she wears black; pl. (Obs.)
      Mourning garments of a black color; funereal drapery.

            Friends weeping, and blacks, and obsequies, and the
            like show death terrible.             --Bacon.

            That was the full time they used to wear blacks for
            the death of their fathers.           --Sir T.
                                                  North.

   5. The part of a thing which is distinguished from the rest
      by being black.

            The black or sight of the eye.        --Sir K.
                                                  Digby.

   6. A stain; a spot; a smooch.

            Defiling her white lawn of chastity with ugly blacks
            of lust.                              --Rowley.

   {Black and white}, writing or print; as, I must have that
      statement in black and white.

   {Blue black}, a pigment of a blue black color.

   {Ivory black}, a fine kind of animal charcoal prepared by
      calcining ivory or bones. When ground it is the chief
      ingredient of the ink used in copperplate printing.

   {Berlin black}. See under {Berlin}.

Source : WordNet®

ivory black
     n : a black pigment made from grinding burnt ivory in oil