fallout

American  

[fawl-out] / ˈfɔlˌaʊt /

Or fall-out

noun

fallouts plural

1. the settling to the ground of airborne particles ejected into the atmosphere from the earth by explosions, eruptions, forest fires, etc., especially such settling from nuclear explosions radioactive fallout.

2. the particles themselves.

3. an unexpected or incidental effect, outcome, or product.

   the psychological fallout of being obese.

4. effects; results.

   emotional fallout from a divorce.

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fallout British  

/ ˈfɔːlˌaʊt /

noun

1. the descent of solid material in the atmosphere onto the earth, esp of radioactive material following a nuclear explosion

2. any solid particles that so descend

3. informal side-effects; secondary consequences

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verb

1. informal to quarrel or disagree

2. (intr) to happen or occur

3. military to leave a parade or disciplinary formation

1. military the order to leave a parade or disciplinary formation

Other Word Forms

Noun Inflected Forms

• fallouts
  plural

Etymology

Origin of fallout

First recorded in 1945–50; noun use of verb phrase fall out

Explanation

Fallout is the cloud of radioactive material that falls from the sky after a nuclear blast. Fear of the effects of fallout is just one reason some people are nervous about nuclear energy. Nuclear fallout settles on the ground and in the atmosphere after a nuclear bomb explodes or a reaction occurs at a damaged nuclear power plant. The dangers of this kind of fallout are enormous, including immediate death and long-term illness caused by breathing and eating the radioactive dust. Another kind of fallout is more figurative — it's any kind of negative effect or result, like the fallout from telling your family you're getting an enormous tattoo.

Example Sentences

See Examples For:

fallout fallouts

Monday’s announcement appeared to leave investors uneasy as well, following hopes that the worst of the culture-war fallout from the logo change was in the rearview.

From MarketWatch ● Jul. 28, 2026

Experts have warned that if the AI bubble pops, the fallout could be bigger than anything Wall Street has ever seen.

From Barron's ● Jul. 28, 2026

Warsh is expected to be generally more supportive of cuts, but will also have to respond to the fallout from the Iranian conflict.

From BBC ● Jul. 22, 2026

What follows — the drained reserves, the mismatched oil, the strained grid and the price we all pay — is the fallout.

From MarketWatch ● Jul. 21, 2026

I wasn’t shaking, wasn’t really bothered at all by the impending fallout.

From "Anthem of a Reluctant Prophet" by Joanne Proulx

Rising prices and a volatile currency have been among the major domestic economic fallouts of Moscow's four-year offensive on Ukraine, which has seen it hit with unprecedented packages of Western sanctions.

From Barron's ● Jun. 30, 2026

The trail of damage from Patterson’s pet project includes money fights, family estrangement and bitter fallouts as friends turned on each other amid efforts to debunk or defend the footage over the years.

From The Wall Street Journal ● Mar. 12, 2026

And South Africa, hosted a successful meeting with no public fallouts.

From BBC ● Aug. 24, 2023

Extended flashbacks fill in the various personal fallouts and professional disappointments that transpired during the 7,000 years in between.

From Los Angeles Times ● Oct. 24, 2021

"COVID-19 fallouts are pushing low-paid workers into even harder situations with little, or no, increase in pay," said Hisashi Yamada, senior economist at Japan Research Institute.

From Reuters ● Oct. 22, 2021