/ Dictionary / Index H headlong: Meaning and Definition of Find definitions for: head•long Pronunciation: (hed'lông", -long"), [key] — adv. with the head foremost; headfirst: to plunge headlong into the water. without delay; hastily: to plunge headlong into work. without deliberation; rashly: to rush headlong into battle. —adj. undertaken quickly and suddenly; made precipitately; hasty: a headlong flight. rash; impetuous: a headlong denunciation. done or going with the head foremost: a headlong dive into the pool. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: headlong (Thesaurus) headlock head louse Related Content Daily Word Quiz: modify Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language