A solid compound containing water molecules combined in a definite ratio as an integral part of the crystal. Often used in combination: pentahydrate
v. hy·drat·ed, hy·drat·ing, hy·drates
1. To rehydrate.
2. To supply water to (a person, for example) in order to restore or maintain fluid balance: "Cold water is the fastest and safest way to hydrate an ordinary athlete" (Jane E. Brody).
To become a hydrate.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.