fallout

1 of 2

noun

fall·​out ˈfȯl-ˌau̇t 

1

a

: the often radioactive particles stirred up by or resulting from a nuclear explosion and descending through the atmosphere

also : other polluting particles (such as volcanic ash) descending likewise

b

: descent (as of fallout) through the atmosphere

2

: a secondary and often lingering effect, result, or set of consequences

have to take a position and accept the political fallout

—Andy Logan

fall out

2 of 2

verb

fell out; fallen out; falling out; falls out

intransitive verb

1

: quarrel

also : to cut off relations over a quarrel

former friends who have fallen out

2

: turn out, happen

expected to be in the States …  , but things fell out otherwise

—Mark Twain

3

a

: to leave one's place in the ranks

b

: to leave a building in order to take one's place in a military formation

Synonyms

Verb

• altercate
• argue
• argufy
• bicker
• brabble
• brawl
• controvert
• dispute
• fight
• hassle
• jar
• quarrel
• quibble
• row
• scrap
• spat
• squabble
• tiff
• wrangle

Examples of fallout in a Sentence

Noun

concerned about the possible political fallout from the scandal

Verb

club members were soon falling out about how to spend the money they'd made washing cars

I had planned to have a sports career, but things fell out otherwise.

Recent Examples on the Web

Noun

Meanwhile, the long-term fallout of Trump's existing tariff announcements is yet to be seen. —Raja Krishnamoorthi, MSNBC Newsweek, 9 Apr. 2025

This Club name has been hit hard by tariff fallout, including a questionable probe by Chinese regulators. —Jim Cramer, CNBC, 9 Apr. 2025

Verb

After falling out of the lead on the second hole, McIlroy regained the top spot and held it throughout most of the rest of the round. —Thomas G. Moukawsher, MSNBC Newsweek, 14 Apr. 2025

Thiel was a major Trump supporter during the 2016 campaign, but later had a falling out with the president and was largely on the sidelines in 2024 even as many of his tech peers rallied behind the Republican leader. —Ari Levy, CNBC, 11 Apr. 2025

Word History

First Known Use

Noun

1946, in the meaning defined at sense 1a

Verb

15th century, in the meaning defined at sense 1

Phrases Containing fallout

• fallout shelter

Rhymes for fallout

• about
• bailout
• blackout
• blowout
• breakout
• burnout
• buyout
• checkout
• closeout
• cutout
• devout
• dropout

Kids Definition

fallout

1 of 2 noun

fall·​out ˈfȯ-ˌlau̇t 

: the often radioactive particles that are stirred up by or result from a nuclear explosion and descend through the atmosphere

fall out

2 of 2 verb

(ˈ)fȯ-ˈlau̇t

1

: to have a quarrel

2

: happen sense 1

Medical Definition

fallout

noun

fall·​out ˈfȯ-ˌlau̇t 

1

: the often radioactive particles stirred up by or resulting from a nuclear explosion and descending through the atmosphere

also : other polluting particles (as volcanic ash) descending likewise

2

: descent (as of fallout) through the atmosphere