anhydride

n. substance formed by dehydration (Chemistry)

In chemistry, an anhydride is a compound that can be considered as derived from another compound by subtracting the molecules of water. For example:2 NaOH - H2O = Na₂OH₂SO₄ - H2O = SO₃Thus sodium oxide is an anhydride of sodium hydroxide, and sulfur trioxide is an anhydride of sulfuric acid.
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Anhydride /an·hy·dride/ any compound derived from a substance, especially an acid, by abstraction of a molecule of water. [more]Anhydride - Community and Resources

Noun
1. a compound formed from one or more other compounds in a reaction resulting in removal of water
(hypernym) compound, chemical compound
(hyponym) acetic anhydride

n. anhydride, substance formed by dehydration (Chemistry)