The Collaborative International Dictionary of English v.0.48:

Hydrate \Hy"drate\, v. t. [imp. & p. p. Hydrated; p. pr. & vb.
   n. Hydrating.]
   To form into a hydrate; to combine with water.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Hydrated \Hy"dra*ted\, a.
   Formed into a hydrate; combined with water.
   [1913 Webster]

WordNet (r) 3.0 (2006):

hydrated
    adj 1: containing combined water (especially water of
           crystallization as in a hydrate) [syn: hydrous,
           hydrated] [ant: anhydrous]