陰いんイオンいんイオンMeanings1nounanion; negative ionchemistryChemistry term for a negatively charged ion. Often contrasted with 陽イオン (cation).See also: 陽イオン塩えん化か物ぶつイオンは代だい表ひょう的てきな陰いんイオンです。The chloride ion is a typical anion.陰いんイオンと陽ようイオンが引ひき合あって結けつ合