/ Dictionary / Index U undouble: Meaning and Definition of Find definitions for: un•dou•ble Pronunciation: (un-dub'ul), [key] — -bled, -bling. to unfold; render single. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. undone undoubted Related Content Daily Word Quiz: acquiesce Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language