/ Dictionary / Index R R.R.: Meaning and Definition of Find definitions for: R.R. Pronunciation: [key] railroad. Right Reverend. rural route. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. r-quality R-rated Related Content Daily Word Quiz: pristine Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language