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headlight

American  
[hed-lahyt] / ˈhɛdˌlaɪt /

noun

  1. a light lights or lamp, usually equipped with a reflector, on the front of an automobile, locomotive, etc.

headlight British  
/ ˈhɛdˌlaɪt /

noun

  1. a powerful light, equipped with a reflector and attached to the front of a motor vehicle, locomotive, etc See also quartz-iodine lamp

"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

Etymology

Origin of headlight

An Americanism dating back to 1860–65; head + light 1

Explanation

If you’re driving a car at night, you’re using your car’s headlights to light up the road in front of you. Headlights are the eyes of a car or train, beaming light to help you see what is ahead. The headlight is an important part of an automobile, and without it you could only drive at night where there are lots of street lights. On unlit roads, a deer might jump in front of your car and just stand there — staring into the light from your headlights. That’s where the expression “like a deer in headlights” comes from, and it means being really still after a shock, like you’re frozen in place.

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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.

Tucker’s other innovations included a padded dashboard for safety, four-wheel independent suspension and a cyclops-like center headlight that rotated with the steering wheel to improve visibility around corners.

From The Wall Street Journal • Apr. 8, 2026

Additionally, please take good care to notice signage regarding segments of the highway where daytime headlight use is required.

From Los Angeles Times • Dec. 29, 2025

Denise Voon, a clinical advisor at The College of Optometrists, said the DfT should "take immediate, actionable steps to support drivers and commission more detailed research, specifically into how headlight regulations need to change".

From BBC • Nov. 4, 2025

Ms Sahota said Beesla had followed his friend home in the Firebird which had a damaged headlight and shattered windscreen.

From BBC • Mar. 10, 2025

Just then, a car came barreling down the road with only one headlight.

From "The Immortal Life of Henrietta Lacks" by Rebecca Skloot

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.