The Collaborative International Dictionary of English v.0.48:

Exsiccate \Ex"sic*cate\ (?; 277), v. t. [imp. & p. p.
   Exsiccated; p. pr. & vb. n. Exsiccating.] [L. exsiccatus,
   p. p. of exsiccare to dry up; ex out + siccare to make dry,
   siccus dry.]
   To exhaust or evaporate moisture from; to dry up. --Sir T.
   Browne.
   [1913 Webster]

WordNet (r) 3.0 (2006):

exsiccate
    v 1: lose water or moisture; "In the desert, you get dehydrated
         very quickly" [syn: exsiccate, dehydrate, dry up,
         desiccate] [ant: hydrate]