or fall-out

[ fawl-out ]
See synonyms for fallout on Thesaurus.com
  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 ).: Compare rainout.

  2. the particles themselves.: Compare rainout.

  1. an unexpected or incidental effect, outcome, or product: the psychological fallout of being obese.

  2. effects; results: emotional fallout from a divorce.

Origin of fallout

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

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use fallout in a sentence

British Dictionary definitions for fallout


/ (ˈfɔːlˌaʊt) /

  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

  1. informal side-effects; secondary consequences

verbfall out (intr, adverb)
  1. informal to quarrel or disagree

  2. (intr) to happen or occur

  1. military to leave a parade or disciplinary formation

sentence substitute
  1. military the order to leave a parade or disciplinary formation

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Idioms and Phrases with fallout


Leave one's place in military ranks, as in After inspection they were ordered to fall out. [First half of 1800s]

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.