The Collaborative International Dictionary of English v.0.48:

Sorghum \Sor"ghum\, n. [NL., probably of Chinese origin.] (Bot.)
   (a) A genus of grasses, properly limited to two species,
       Sorghum Halepense, the Arabian millet, or Johnson grass
       (see Johnson grass), and Sorghum vulgare, the Indian
       millet (see Indian millet, under Indian).
   (b) A variety of Sorghum vulgare, grown for its saccharine
       juice; the Chinese sugar cane.
       [1913 Webster]

WordNet (r) 3.0 (2006):

sorghum
    n 1: economically important Old World tropical cereal grass
    2: annual or perennial tropical and subtropical cereal grasses:
       sorghum [syn: genus Sorghum, Sorghum]
    3: made from juice of sweet sorghum [syn: sorghum, sorghum
       molasses]

Moby Thesaurus II by Grady Ward, 1.0:

28 Moby Thesaurus words for "sorghum":
   ambrosia, artificial sweetener, blackstrap, calcium cyclamate,
   cane syrup, clover honey, comb honey, corn syrup, cyclamates,
   edulcoration, honey, honeycomb, honeydew, honeypot, maple syrup,
   molasses, nectar, saccharification, saccharin, sodium cyclamate,
   sugar, sugar-making, sugaring off, sweetener, sweetening, sweets,
   syrup, treacle