- lightning - abrupt electric discharge from cloud to cloud or from cloud to earth accompanied by the emission of light
--1 is a kind of atmospheric electricity
--1 has particulars:forked lightning, chain lightning; thunderbolt, bolt, bolt of lightning - lightning - the flash of light that accompanies an electric discharge in the atmosphere (or something resembling such a flash); can scintillate for a second or more
--2 is a kind of flash
--2 has particulars: heat lightning; sheet lighting - lightning - the flash of light that accompanies an electric discharge in the atmosphere (or something resembling such a flash); can scintillate for a second or more