/ Dictionary / Index R robber fly: Meaning and Definition of Find definitions for: rob'ber fly" Pronunciation: [key] any of numerous swift-flying, often large, dipterous insects of the family Asilidae that are predaceous on other insects. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. robber baron robber frog Related Content Daily Word Quiz: censure Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language