/ Dictionary / Index R RDB: Meaning and Definition of Find definitions for: RDB Pronunciation: [key] — Mil. Mil. Research and Development Board. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. RD&E RDD Related Content Daily Word Quiz: dissonant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language