fallout

American  

[fawl-out] / ˈfɔlˌaʊt /

Or fall-out

noun

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

Etymology

Origin of fallout

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

Example Sentences

The third season of “Mormon Wives” featured the fallout from an explosive crossover with Hulu’s other reality series, which follows former Bravo star Lisa Vanderpump and her staff at various luxury European estates.

From Los Angeles Times • Apr. 3, 2026

But for now the primary fallout from the tariffs in the US has been business strains and higher prices for consumers.

From BBC • Apr. 2, 2026

Anthropic is racing to contain the fallout after accidentally exposing the underlying instructions it uses to direct Claude Code, the popular artificial-intelligence agent app that has won the company an edge with developers and businesses.

From The Wall Street Journal • Apr. 1, 2026

The company was also struggling to manage the fallout from CEO Elon Musk’s role leading the U.S.

From MarketWatch • Apr. 1, 2026

Even relative freedom from fallout, well short of the 95 percent cleanliness Strauss and the scientists had mentioned, could be achieved only from reducing yields.

From "Big Science" by Michael Hiltzik