Etymologically
Log in

fallout

History Permalink

Etymology and origin of the English word fallout

Confidence
Established
Formation
Compound
First attested
1725 T. Fuller, Directions, Counsels and Cautions
Ultimate origins
Old English feallanEnglish out
Etymology tree
inherited borrowed derived
English fall
English fallout
From the same root
English rainfall ← fall

Pronunciation

  • UK: /ˈfɔːlaʊt/[1]
  • US: /ˈfɔlˌaʊt/[1]

Etymology

It is formed from English fall + out,[2][3][4] after the phrasal verb fall out;[2][5][6] for the sense "quarrel" the OED compares the earlier noun falling-out.[2]

Earliest recorded meaning

A disagreement, a quarrel: 1725, in T. Fuller's Directions, Counsels and Cautions.[2]

Semantic evolution

The modern word belongs to the nuclear age: radioactive particles carried up by a nuclear explosion and falling back as dust or in rain are recorded from 1946, in the Military Engineer,[2] from 1949 in Merriam-Webster[6] and 1950 in Etymonline,[3] and Dictionary.com dates the noun to 1945–50.[5] The figurative sense, the usually unwelcome consequences of an action or event, followed in 1954, in the magazine “Time”,[2][4] and in 1956 the word was first used of dust from industry or volcanoes settling on the ground.[2][6]

Timeline

  • 1725 – a quarrel.[2]
  • 1946 – radioactive particles falling after a nuclear explosion.[2]
  • 1954 – the consequences or aftermath of an event.[2]
  • 1956 – other airborne particles falling to the ground.[2]

Meanings

Noun

  1. Radioactive particles thrown into the atmosphere by a nuclear explosion that fall back to earth; also their falling.[7][6][2]
  2. Other particles, such as volcanic ash or industrial dust, that settle from the air.[6][2][7]
  3. The side effects or consequences of something, usually bad or unexpected: the political fallout from the scandal.[7][6][2]
  4. A disagreement or quarrel.[2]

References

  1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f g h i j k l m n o Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
  3. ^ a b Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  4. ^ a b Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
  5. ^ a b Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
  6. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
  7. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins
Cite this entry

“Fallout.” Etymologically, 25 Oct. 2026, etymologically.com/en/fallout. Accessed 26 Oct. 2026.

Last edited on . ·