/ Dictionary / Index I -idium: Meaning and Definition of Find definitions for: -idium Pronunciation: [key] a diminutive suffix, corresponding toused in zoological, biological, botanical, anatomical, and chemical terms: peridium. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. idiotype idle Related Content Daily Word Quiz: crutiny Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language