Source : Webster's Revised Unabridged Dictionary (1913)

Vermilion \Ver*mil"ion\, n. [F. vermillon. See {Vermeil}.]
   1. (Chem.) A bright red pigment consisting of mercuric
      sulphide, obtained either from the mineral cinnabar or
      artificially. It has a fine red color, and is much used in
      coloring sealing wax, in printing, etc.

   Note: The kermes insect has long been used for dyeing red or
         scarlet. It was formerly known as the worm dye,
         vermiculus, or vermiculum, and the cloth was called
         vermiculatia. Hence came the French vermeil for any red
         dye, and hence the modern name vermilion, although the
         substance it denotes is very different from the kermes,
         being a compound of mercury and sulphur. --R. Hunt.

   2. Hence, a red color like the pigment; a lively and
      brilliant red; as, cheeks of vermilion.

Vermilion \Ver*mil"ion\, v. t.
   To color with vermilion, or as if with vermilion; to dye red;
   to cover with a delicate red.

Source : WordNet®

vermilion
     adj : of a vivid red to reddish-orange color [syn: {vermillion}, {cinnabar},
            {Chinese-red}]
     n : a variable color that is vivid red but sometimes with an
         orange tinge [syn: {scarlet}, {orange red}]
     v : color vermilion