/ Dictionary / Index D dup: Meaning and Definition of Find definitions for: dup Pronunciation: (dup), [key] — dupped, dup•ping. to open. dup. Pronunciation: [key] duplicate. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. duotype dupe Related Content Daily Word Quiz: portent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language