Wordnet 3.0
NOUN (1)
1. 
 pigment of cadmium sulfide and barium sulfate varying in hue from lemon yellow to orange; 
The Collaborative International Dictionary of English v.0.48:
Yellow \Yel"low\, n.
   1. A bright golden color, reflecting more light than any
      other except white; the color of that part of the spectrum
      which is between the orange and green. "A long motley coat
      guarded with yellow." --Shak.
      [1913 Webster]
   2. A yellow pigment.
      [1913 Webster]
   Cadmium yellow, Chrome yellow, Indigo yellow, King's
   yellow, etc. See under Cadmium, Chrome, etc.
   Naples yellow, a yellow amorphous pigment, used in oil,
      porcelain, and enamel painting, consisting of a basic lead
      metantimonate, obtained by fusing together tartar emetic
      lead nitrate, and common salt.
   Patent yellow (Old Chem.), a yellow pigment consisting
      essentially of a lead oxychloride; -- called also
      Turner's yellow.
      [1913 Webster]
The Collaborative International Dictionary of English v.0.48:
Cadmium \Cad"mi*um\, n. [NL. See Cadmia.] (Chem.)
   A comparatively rare element related to zinc, and occurring
   in some zinc ores. It is a white metal, both ductile and
   malleable. Symbol Cd. Atomic weight 111.8. It was discovered
   by Stromeyer in 1817, who named it from its association with
   zinc or zinc ore.
   [1913 Webster]
   Cadmium yellow, a compound of cadmium and sulphur, of an
      intense yellow color, used as a pigment.
      [1913 Webster]
WordNet (r) 3.0 (2006):
cadmium yellow
    n 1: pigment of cadmium sulfide and barium sulfate varying in
         hue from lemon yellow to orange