lightning

American  

[lahyt-ning] / ˈlaɪt nɪŋ /

noun

1. a brilliant electric spark discharge in the atmosphere, occurring within a thundercloud, between clouds, or between a cloud and the ground.

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verb (used without object)

lightninged, lightning

1. to emit a flash or flashes of lightning (often used impersonally with it as subject).

   If it starts to lightning, we'd better go inside.

adjective

1. of, relating to, or resembling lightning, especially in regard to speed of movement: lightning speed.

   lightning flashes;

   lightning speed.

idioms

1. catch lightning in a bottle. see catch lightning in a bottle.

lightning British  

/ ˈlaɪtnɪŋ /

noun

1. 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

2. (modifier) fast and sudden

   a lightning raid

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lightning Scientific  

/ līt′nĭng /

1. A flash of light in the sky caused by an electrical discharge between clouds or between a cloud and the Earth's surface. The flash heats the air and usually causes thunder. Lightning may appear as a jagged streak, as a bright sheet, or in rare cases, as a glowing red ball.

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lightning Cultural  

1. An electrical discharge from clouds that have acquired an electrical charge, usually occurring during storms. (See thunder.)

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lightning More Idioms  

More idioms and phrases containing lightning

• like greased lightning
• quick as a wink (lightning)

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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; see lighten ¹, -ing ¹

Compare meaning

How does lightning compare to similar and commonly confused words? Explore the most common comparisons:

• lightning vs. lightening

Explanation

When you see sudden bright flashes of light in the sky, you're seeing lightning, the release of electricity between clouds or the ground. Lightning can be scary, and if it strikes a person, it can kill. You can tell how close the lightning is by how long the delay is between the light and the sound of the rolling roar or crack of thunder that accompanies it. If they're close together, get inside, quick! Because lighting strikes so fast, we use its name for other speedy things, like the lightning-fast service at a good coffee shop.

Example Sentences

That’s the finishing time of Lightning, a Chinese humanoid robot that won the Beijing Half-Marathon while beating the human world record.

From The Wall Street Journal • Apr. 28, 2026

Lightning, one of more than 100 robots running the Beijing E-Town, avoided a serious mishap and crossed the finish line in a record 50 minutes, 26 seconds.

From Los Angeles Times • Apr. 23, 2026

Lightning and two siblings from Honor swept the podium.

From The Wall Street Journal • Apr. 20, 2026

Although many crashed or collided with robot brethren, Lightning avoided a serious mishap and crossed the finish line in 50 minutes, 26 seconds.

From Los Angeles Times • Apr. 20, 2026

Lightning flashed, and thunder rolled over the hills.

From "Prisoner B-3087" by Alan Gratz