"a negatively charged ion, which moves toward the anode (q.v.) during electrolysis," 1834, proposed by the Rev. William Whewell, English polymath, and published by English physicist Michael Faraday, from Greek anion "(thing) going up," neuter past participle of anienai "go up," from ana "up" (see ana-) + ienai "go" (from PIE root *ei- "to go"). Related: Anionic.