/ Dictionary / Index N nightlong: Meaning and Definition of Find definitions for: night•long Pronunciation: (adj.nīt'lông", -long"adv.nīt'lông', -long'), [key] — adj. lasting all night: a nightlong snowfall. —adv. through the entire night: They typed nightlong to finish the reports. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: nightlong (Thesaurus) night lizard nightly Related Content Daily Word Quiz: vertigo Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language