The Collaborative International Dictionary of English v.0.48:

millet \mil"let\ (m[i^]l"l[e^]t), n. [F., dim. of mil, L.
   milium; akin to Gr. meli`nh, AS. mil.] (Bot.)
   The name of several cereal and forage grasses which bear an
   abundance of small roundish grains. The common millets of
   Germany and Southern Europe are Panicum miliaceum, and
   Setaria Italica.

   Note:

   Arabian millet is Sorghum Halepense.

   Egyptian millet or

   East Indian millet is Penicillaria spicata.

   Indian millet is Sorghum vulgare. (See under Indian.)


   Italian millet is Setaria Italica, a coarse, rank-growing
      annual grass, valuable for fodder when cut young, and
      bearing nutritive seeds; -- called also Hungarian grass.


   Texas millet is Panicum Texanum.

   Wild millet, or

   Millet grass, is Milium effusum, a tall grass growing in
      woods.
      [1913 Webster]

WordNet (r) 3.0 (2006):

millet
    n 1: any of various small-grained annual cereal and forage
         grasses of the genera Panicum, Echinochloa, Setaria,
         Sorghum, and Eleusine
    2: French painter of rural scenes (1814-1875) [syn: Millet,
       Jean Francois Millet]
    3: small seed of any of various annual cereal grasses especially
       Setaria italica

Moby Thesaurus II by Grady Ward, 1.0:

20 Moby Thesaurus words for "millet":
   breakfast food, cereal, cornflakes, dry cereal, farina, frumenty,
   grits, gruel, hasty pudding, hominy grits, hot cereal, kasha,
   loblolly, mush, oatmeal, porridge, puffed rice, puffed wheat,
   rolled oats, wheatflakes



Easton's 1897 Bible Dictionary:

Millet
   (Heb. dohan; only in Ezek. 4:9), a small grain, the produce of
   the Panicum miliaceum of botanists. It is universally cultivated
   in the East as one of the smaller corn-grasses. This seed is the
   cenchros of the Greeks. It is called in India warree, and by the
   Arabs dukhan, and is extensively used for food, being often
   mixed with other grain. In this country it is only used for
   feeding birds.