fallout

1 of 2

noun

fall·​out ˈfȯl-ˌau̇t How to pronounce fallout (audio)
Synonyms of falloutnext
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

See All Synonyms & Antonyms in Thesaurus

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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Noun
The political fallout over the measure is reverberating the most among Democrats, with Senate Minority Leader Chuck Schumer (D-N.Y.) facing fury from much of his party over his decision to provide the votes necessary for the measure to get through the Senate. — Mychael Schnell, The Hill, 14 Mar. 2025 Nearly a year later, the university continues to face fallout from the protests. — Jaclyn Diaz, NPR, 14 Mar. 2025
Verb
But on one subject, the whole dozen fell out of the cart and smashed on the floor. — arkansasonline.com, 10 Mar. 2025 Conversely, Jim cautioned against buying any restaurant stocks right now because the group has fallen out of favor. — Kevin Stankiewicz, CNBC, 10 Mar. 2025 See All Example Sentences for fallout

Word History

First Known Use

Noun

1946, in the meaning defined at sense 1a

Verb

15th century, in the meaning defined at sense 1

Time Traveler
The first known use of fallout was in the 15th century

Phrases Containing fallout

Rhymes for fallout

See All Rhymes for fallout

Browse Nearby Words

fallout
fall out
See all Nearby Words

Cite this Entry

“Fallout.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/fallout. Accessed 23 Mar. 2025.

Copy Citation

Share

Kids Definition

fallout

1 of 2 noun
fall·​out ˈfȯ-ˌlau̇t How to pronounce fallout (audio)
: 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 How to pronounce fallout (audio)
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

More from Merriam-Webster on fallout

Nglish: Translation of fallout for Spanish Speakers

Britannica.com: Encyclopedia article about fallout

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Popular in Grammar & Usage

See More

The Difference Between 'i.e.' and 'e.g.'

How to Use Em Dashes (—), En Dashes (–) , and Hyphens (-)

Why is '-ed' sometimes pronounced at the end of a word?

What's the difference between 'fascism' and 'socialism'?

More Commonly Misspelled Words
See More

Popular in Wordplay

See More

What do SCOTUS, POTUS, and FLOTUS mean?

Flower Etymologies For Your Spring Garden

More Words with Remarkable Origins

Terroir, Oenophile, & Magnum: Ten Words About Wine

8 Words for Lesser-Known Musical Instruments
See More

Popular Features

See More

The Difference Between 'i.e.' and 'e.g.'

What do SCOTUS, POTUS, and FLOTUS mean?

Flower Etymologies For Your Spring Garden
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Word Game Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
Missing Letter A daily crossword with a twist
dog-in-disguise
Rhyme Disguise Quiz Pair up words that look different but sound alike.
See All