headlight

American  

[hed-lahyt] / ˈhɛdˌlaɪt /

noun

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

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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

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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.

Example Sentences

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

It's an issue that has even reached the United Nations - it will mandate all new cars to automatically adjust their headlight levels.

From BBC • Feb. 18, 2026

Although headlight glare does affect younger people, age is thought to be a factor.

From BBC • Feb. 18, 2026

Early this year, Rivian recalled 17,260 vehicles in the U.S. over a headlight issue that could reduce visibility and increase the risk of a crash.

From Los Angeles Times • Dec. 3, 2025

If you know how much light the headlight puts out—if the headlight is a standard candle—you can tell how bright the headlight will appear at any given distance.

From "Zero: The Biography of a Dangerous Idea" by Charles Seife

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