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Pronunciation: gas


  1. A thin fluid, such as air, capable of indefinite expansion but convertible by compression and cold into a liquid and, eventually, a solid.
  2. In clinical practice, a liquid entirely in its vapor phase at one atmosphere of pressure because ambient temperature is above its boiling point.

[coined by J.B. van Helmont, Flemish chemist and physician, 1579–1644]

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© Copyright 2018 Wolters Kluwer. All Rights Reserved. Review Date: Sep 19, 2016.