/ Dictionary / Index I idio-: Meaning and Definition of Find definitions for: idio- Pronunciation: [key] a combining form meaning “proper to one,” “peculiar,” used in the formation of compound words: idiomorphic. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. -idine idioblast Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language