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Medical Term:


Pronunciation: hi-dra'shun


  1. Chemically, the addition of water; differentiated from hydrolysis, where the union with water is accompanied by a splitting of the original molecule and the water molecule.
  2. Clinically, the taking in of water; used commonly in the sense of reduced hydration or dehydration.
  3. The formation of a shell of water molecules around a molecular entity.

See Also: solvation

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