hydrate (n.) Look up hydrate at Dictionary.com
"compound of water and another chemical," 1802, from French hydrate, coined c. 1800 by French chemist Joseph-Louis Proust (1754-1826) from Greek hydr-, stem of hydor "water" (see water (n.1)). Also formerly applied to compounds formed on the same type as H2O.
hydrate (v.) Look up hydrate at Dictionary.com
1812 (implied in hydrated), "to form a hydrate, combine chemically with water," from hydrate (n.), perhaps modeled on French hydrater. From 1947 as "to restore moisture;" from Greek hydr-, stem of hydor "water" (see water (n.1)) + -ate (2). Related: Hydrating.