hydrate

Concise Oxford English Dictionary © 2008 Oxford University Press:
hydrate

▶noun /ˈhʌɪdreɪt/ Chemistry a compound in which water molecules are chemically bound to another compound or an element. ▶verb /hʌɪˈdreɪt/ cause to absorb or combine with water.

– derivatives
hydratable adjective,
hydration noun,
hydrator noun.

– origin C19: coined in Fr. from Gk hudōr ‘water’.