The Collaborative International Dictionary of English v.0.48:

Mung \Mung\ (m[u^]ng), n. [Hind. m[=u]ng.] (Bot.)
   Green gram, a kind of legume (pulse) (Vigna radiata syn.
   Phaseolus aureus, syn. Phaseolus Mungo), grown for food
   in British India; called also gram, mung bean, Chinese
   mung bean, and green-seeded mung bean. It is an erect,
   bushy annual producing edible green or yellow seeds, and
   edible pods and young sprouts. --Balfour (Cyc. of India).
   [1913 Webster]