A mixture of odorless gases found in the atmosphere in the following approximate percentages by volume after water vapor has been removed: oxygen, 20.95; nitrogen, 78.08; argon 0.93; carbon dioxide, 0.03; other gases, 0.01. Formerly used to mean any respiratory gas, regardless of its composition.
[G. aēr; L. aer]
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Examples: glitazone, GI cocktail, etc.