Meaning of ION in English

n. an atom or group of atoms that has lost one or more electrons (= CATION), or gained one or more electrons (= ANION). ion exchange the exchange of ions of the same charge between a usu. aqueous solution and a solid, used in water-softening etc. ion exchanger a substance or equipment for this process.

[ Gk, neut. pres. part. of eimi go ]

Concise Oxford English dictionary.      Краткий оксфордский словарь английского языка.