/ Dictionary / Index R Roman arch: Meaning and Definition of Find definitions for: Ro'man arch' Pronunciation: [key] a semicircular arch. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Roman alphabet Roman brick Related Content Daily Word Quiz: cygnet Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language