Source : Webster's Revised Unabridged Dictionary (1913)

Hydrous \Hy"drous\, a. [Gr. "y`dwr water.]
   1. Containing water; watery.

   2. (Chem.) Containing water of hydration or crystallization.

Source : WordNet®

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