headlamp vs headlight

headlamp

noun
  • An individual headlight, particularly of a motor vehicle. 

  • A flashlight worn on the head. 

headlight

noun
  • 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. 

  • A woman's breast. 

  • A jewel; especially a diamond. 

  • Lysergic acid diethylamide (LSD). 

  • A woman's erect nipples, partially masked by clothing. 

How often have the words headlamp and headlight occurred in a corpus of books? (source: Google Ngram Viewer )