The Collaborative International Dictionary of English v.0.48:

Rouge \Rouge\, n. [F.]
   1. (Chem.) A red amorphous powder consisting of ferric oxide.
      It is used in polishing glass, metal, or gems, and as a
      cosmetic, etc. Called also crocus, jeweler's rouge,
      etc.
      [1913 Webster]

   2. A cosmetic used for giving a red color to the cheeks or
      lips. The best is prepared from the dried flowers of the
      safflower, but it is often made from carmine. --Ure.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Crocus \Cro"cus\ (kr[=o]"k[u^]s), n. [L., saffron, fr. Gr.
   kro`kos; cf. Heb. kark[=o]m, Ar. kurkum, Skr. ku[.n]kuma.]
   1. (Bot.) A genus of iridaceous plants, with pretty blossoms
      rising separately from the bulb or corm. Crocus vernus
      is one of the earliest of spring-blooming flowers; Crocus
      sativus produces the saffron, and blossoms in the autumn.
      [1913 Webster]

   2. (Chem.) A deep yellow powder; the oxide of some metal
      calcined to a red or deep yellow color; esp., the oxide of
      iron (Crocus of Mars or colcothar) thus produced from
      salts of iron, and used as a polishing powder.
      [1913 Webster]

   Crocus of Venus (Old Chem.), oxide of copper.
      [1913 Webster]

WordNet (r) 3.0 (2006):

crocus
    n 1: any of numerous low-growing plants of the genus Crocus
         having slender grasslike leaves and white or yellow or
         purple flowers; native chiefly to the Mediterranean region
         but widely cultivated