What is the meaning of Headlight?

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 woman's erect nipples, partially masked by clothing.

A jewel; especially a diamond.

Lysergic acid diethylamide (LSD).

Source: wiktionary.org