Meaning of tetrahydrate

tet•ra•hy•drate

Pronunciation: (te"tru-hī'drāt), [key]
— n. Chem.
  1. a hydrate that contains four molecules of water, as potassium sodium tartrate, KNaCHO&raiseddot;4HO.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.