lightning
Americannoun
verb (used without object)
adjective
idioms
noun
-
a flash of light in the sky, occurring during a thunderstorm and caused by a discharge of electricity, either between clouds or between a cloud and the earth
-
(modifier) fast and sudden
a lightning raid
Closer Look
As storm clouds develop, the temperature at the top of the cloud becomes much cooler than that at the bottom. For reasons that scientists still do not understand, this temperature difference results in the accumulation of negatively charged particles near the base and positively charged particles near the top of the storm cloud. The negatively charged particles repel the electrons of atoms in nearby objects, such as the bases of other storm clouds or tall objects on the ground. Consequently, these nearby objects take on a positive charge. The difference in charge, or voltage, builds until an electric current starts to flow between the objects along a pathway of charged atoms in the air. The current flow heats up the air to such a degree that it glows, generating lightning. Initially, a bolt of lightning carrying a negative charge darts from one storm cloud to another or from a storm cloud to the ground, leaving the bottom of the cloud with a positive charge. In response, a second bolt (reverse lightning) shoots in the opposite direction (from the other storm cloud or the ground) as the mass of negative charges on it moves back to neutralize the positive charge on the bottom of the first cloud. The heat generated by the lightning causes the air to expand, in turn creating very large sound waves, or thunder.
Etymology
Origin of lightning
First recorded in 1350–1400; Middle English, variant of lightening; lighten 1, -ing 1
Compare meaning
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Scientists believe they have recorded electrical activity in the Martian atmosphere for the first time, suggesting the planet is capable of lightning.
From BBC
Chaparral ecosystems, including the shrubby plants and oak trees that cover the Santa Monica Mountains, have historically experienced fire every 30 to 130 years — primarily due to lightning strikes.
From Los Angeles Times
And in the AI era, in which innovation and risk are changing market dynamics at lightning speed, reducing transparency would be a step backward at exactly the wrong time.
From Barron's
The divide between the Upside Down and Hawkins is flung open as fields of flowers wilt, clouds turn black and bright red flashes of lightning fill the sky.
From BBC
Named for her younger sister, the touching “Kimberly” is based on their childhood observation of a barn lightning strike and flooding.
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.