[ hed-lawng, -long ]
/ ˈhɛdˌlɔŋ, -ˌlɒŋ /


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.


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.

Origin of headlong

1350–1400; Middle English hedlong, earlier hedling. See head, -ling2

Related forms

head·long·ness, noun

Can be confused

headlong headstrong
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for headlong

British Dictionary definitions for headlong


/ (ˈhɛdˌlɒŋ) /

adverb, adjective

with the head foremost; headfirst
with great haste


archaic (of slopes, etc) very steep; precipitous
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012