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.
the particles themselves. Compare rainout.
an unexpected or incidental effect, outcome, or product: the psychological fallout of being obese.
effects; results: emotional fallout from a divorce.
Also, fall-out.

1945–50; noun use of verb phrase fall out

Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source Link To fallout
World English Dictionary
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
3.  informal side-effects; secondary consequences
4.  informal to quarrel or disagree
5.  (intr) to happen or occur
6.  military to leave a parade or disciplinary formation
sentence substitute
7.  military the order to leave a parade or disciplinary formation

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source
Word Origin & History

"radioactive particles," 1950, from fall (v.) + out.
Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
Example sentences
Thus with a steadily decreasing radioactivity fallout the dose rate was not
  dangerous at all.
The collected fallout was measured daily for the amount of gross beta
  radioactivity present.
Tells about the fallout, both in human terms and legally, surrounding the
  research into her linguistic abilities.
That's not to say that the economy has suffered no fallout from the subprime
Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature