/ Dictionary / Index O onion dome: Meaning and Definition of Find definitions for: on'ion dome" Pronunciation: [key] — Archit. Archit. a bulbous, domelike roof ending in a sharp point, characteristically used in Russian Orthodox church architecture to cover cupolas or towers. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. onion onion rings Related Content Daily Word Quiz: benevolent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language