/ Dictionary / Index P prolong: Meaning and Definition of Find definitions for: pro•long Pronunciation: (pru-lông', -long'), [key] — v.t. to lengthen out in time; extend the duration of; cause to continue longer: to prolong one's stay abroad. to make longer in spatial extent: to prolong a line. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: prolong (Thesaurus) prologuize prolongate Related Content Daily Word Quiz: candor Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language