adjective
adverb
Etymology
Origin of headfirst
Explanation
When you do something headfirst, your head leads the way. For example, a boy might show off by diving headfirst into a chilly lake. The adverb headfirst is useful for describing a dive or a movement that leads with the head. A stormy ocean might fling a swimmer headfirst onto the beach, or an unlucky skier could slide headfirst down a mountain. You can also use headfirst in a more figurative way, to describe something that's done impulsively, or in a foolishly hasty manner: "He plunged headfirst into this new relationship two days after breaking up with his girlfriend."
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Dramatic video footage obtained by TMZ shows the boy falling headfirst down the ride’s 50-foot-tall waterfall just behind the flume that he had exited.
From Los Angeles Times ● Jun. 24, 2026
Weston said that anyone who fancies "throwing themselves headfirst down a mountain" should take the opportunity.
From BBC ● Feb. 16, 2026
Mendoza’s 12-yard touchdown run—which saw him break through one tackle, spin 360 degrees, and leap headfirst across the goal line—gave Indiana a 24-14 lead.
From The Wall Street Journal ● Jan. 20, 2026
It was more than just romantic; it was the push I needed to dive headfirst back into studying.
From Salon ● Jan. 18, 2026
Alex threw himself headfirst, flat on his stomach.
From "Stormbreaker" by Anthony Horowitz
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
