/ Dictionary / Index I -idion: Meaning and Definition of Find definitions for: -idion Pronunciation: [key] a diminutive suffix occurring in loanwords from Greek:Cf. -idium. enchiridion. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. idiomorphic idiopathic Related Content Daily Word Quiz: mamba Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language