/ Dictionary / Index I inion: Meaning and Definition of Find definitions for: in•i•on Pronunciation: (in'ē-un), [key] — n. Craniom. a point at the external occipital protuberance of the skull. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: inion (Thesaurus) inimitable iniquitous Related Content Daily Word Quiz: lyceum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language