Other forms: lightnings
Lightning is the sudden bright electric flash that cuts across a stormy sky. A flash of lightning, struck by lightning, lightning storm.
The flash heats the air to several times the temperature of the sun's surface, and the thunder is that air expanding — counting the seconds between the two gives the distance, about three seconds to the kilometre. Lightning does strike the same place twice, tall buildings routinely. Note the spelling, which drops the e of lightening.
1nounlightningThe bright electric flash in a storm.
“Lightning struck the old oak tree and split it in half.”
lightning is an electrical discharge.
Lighten plus -ing, from light. Lightening, meaning making lighter, is the same word with the e kept.
From light(e)n + -ing. a doublet of lightening.
Etymology from Wiktionary, CC BY-SA