The Collaborative International Dictionary of English v.0.48:

Manducate \Man"du*cate\, v. t. [imp. & p. p. Manducated; p.
   pr. & vb. n. Manducating.] [L. manducatus, p. p. of
   manducare to chew. See Manger.]
   To masticate; to chew; to eat. [R.] --Jer. Taylor.
   [1913 Webster]

WordNet (r) 3.0 (2006):

manducate
    v 1: chew (food); to bite and grind with the teeth; "He jawed
         his bubble gum"; "Chew your food and don't swallow it!";
         "The cows were masticating the grass" [syn: chew,
         masticate, manducate, jaw]