D defs.my
Entry 1 sense Webster, 1913

Hydration

/hīd-rāsh'-ən/ · Hy·dra·tion · IPA /haɪˈdɹeɪʃən/
01 n. The act of becoming, or state of being, a hydrate.
  1. 1.
    The act of becoming, or state of being, a hydrate.(Chem.)
Phrases & compounds
Water of hydration — water chemically combined with some substance to form a hydrate; -- distinguished from water of crystallization.