headlight

From head +‎ light.

• (General American) IPA^(key): /ˈhɛdˌlaɪt/

• Audio (General Australian):

  (file)

headlight (plural headlights)

1. A bright light, with a lens and reflector, on the front of a motor vehicle (or originally a ship or train), designed to illuminate the road when driving at night; normally one of a pair.
   • 2026 January 8, Drew Reagan, “A driving source of light pollution: How car headlights are reshaping the nighttime environment”, in DarkSky International‎^[1]:

     Improving how headlights are designed and controlled does not have to mean choosing between environmental protection and public safety. Smarter lighting that reduces unnecessary brightness and glare can benefit wildlife, improve driver comfort, and support safer nighttime travel.

2. (US, slang, vulgar, chiefly in the plural) A woman's breast.
   • 1993, Quantum Leap, season 5, episode 14, spoken by Al Calavicci (Dean Stockwell):

     Oh, well. She's got... great... casabas. […] Well, you know. Melons. […] Hoo-has? Honkers? Hooters? Headlights? Uh... tatas? Teeters? Tweeters? Tom-toms? Tetons? […] I'm trying to say it. Uh, meatballs. Mangoes. Cream pies. Cupcakes? Uh... bangers? Bouncers? Bulumbas? […] Bazongas? Breasts! I said it.

3. (Canada, slang, vulgar, chiefly in the plural) A woman's erect nipples, partially masked by clothing.
4. (US, slang, chiefly in the plural) A jewel; especially a diamond.
5. (US, slang, chiefly in the plural) Lysergic acid diethylamide (LSD).

• (motor vehicle light): headlamp
• (breast): See also Thesaurus:breast.
• (nipple): See also Thesaurus:nipples.

• light

• dome light
• fog lamp
• idiot light
• indicator
• sidelight
• taillight

• Eric Partridge (2005), “headlights”, in Tom Dalzell and Terry Victor, editors, The New Partridge Dictionary of Slang and Unconventional English, volume 1 (A–I), London; New York, N.Y.: Routledge, →ISBN, page 979.
• headlight on Wikipedia.Wikipedia

• lighthead