Headlight

noun

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