An atom or group of atoms carrying an electric charge by virtue of having gained or lost one or more electrons. Ions charged with negative electricity (anions) travel toward a positive pole (anode); those charged with positive electricity (cations) travel toward a negative pole (cathode). Ions may exist in solid, liquid, or gaseous environments, although those in liquid (electrolytes) are more common and familiar.
[G. ion, going]
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Examples: glitazone, GI cocktail, etc.