/ Dictionary / Index R RO.: Meaning and Definition of Find definitions for: RO. Pronunciation: [key] See ro. Pronunciation: [key] recto. roan. rood. R.O. Pronunciation: [key] Receiving Office. Receiving Officer. Regimental Order. Royal Observatory. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: ro (Thesaurus) R.N.W.M.P. ROA Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language