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

The two-day visit is expected to see the presidents sign a slate of economic agreements and discuss the fallout from the US-Iran war.

From Barron's ● Sep. 2, 2026

Muscat, who was never linked to the murder, stepped down in January 2020 due to the political fallout from the assassination.

From BBC ● Sep. 2, 2026

The new season will explore the fallout and tension in domestic and international relationships, and the marital strife in between.

From Los Angeles Times ● Sep. 1, 2026

Over the course of the past week, the fallout for Good Good has continued to pile up.

From The Wall Street Journal ● Aug. 29, 2026

The cometary impact and fireball would simulate all effects of a one- megaton nuclear burst, including the mushroom cloud, with two exceptions: there would be no gamma radiation or radioactive fallout.

From "Cosmos" by Carl Sagan

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

Bejarano cited recent articles by Times critic Mark Swed and New Yorker critic Alex Ross that indicted boards for some newsworthy artistic fallouts.

From Los Angeles Times ● May 8, 2024

While Cristiano Ronaldo and Jadon Sancho were forced to leave United after fallouts with the Dutch manager, Rashford has been reintegrated - and showed why he has the trust of Ten Hag.

From BBC ● Feb. 1, 2024

"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