noun Physical Chemistry.
- a negatively charged ion, as one attracted to the anode in electrolysis.
- any negatively charged atom or group of atoms (opposed to cation).
- a negatively charged ion; an ion that is attracted to the anode during electrolysisCompare cation
“a negatively charged ion, which moves toward the anode (q.v.) during electrolysis,” 1834, proposed by the Rev. William Whewell (1794-1866), 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” (see ion).
- A negatively charged ion, especially one that migrates to the anode in electrolysis.
- An ion with net negative charge, having more electrons than protons. In electrolysis, anions migrate to a positively charged anode. Compare cation.