/ Dictionary / Index C cation: Meaning and Definition of Find definitions for: cat•i•on Pronunciation: (kat'ī"un, -on), [key] — n. Physical Chem. a positively charged ion that is attracted to the cathode in electrolysis. any positively charged atom or group of atoms (opposed to anion). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: cation (Thesaurus) Catiline cationic detergent Related Content Daily Word Quiz: careening Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language