A bar mounted on the roof of a vehicle, such as a police car, with rotating beacons or other lights to provide a visual warning.

Alternative spelling of light curve

plural of lightcurve

plural of lightning bug

(US, informal) Applejack.

plural of lightning rod

A relatively rare form of cloud-to-ground lightning which appears to break up into a string of short, bright sections, and lasts longer than the usual discharge channel.

plural of lightcone

Alternative spelling of light cone

plural of lighthouse keeper