fallout

Short definition from Wiktionary

Noun

1. 1
   The event of small airborne particles falling to the ground in significant quantities as a result of major industrial activity, volcano eruption, sandstorm, nuclear explosion, etc.
2. 2
   The particles themselves.
3. 3
   A negative side effect; an undesirable or unexpected consequence.
4. 4
   A declined offer in a sales transaction when acceptance was presumed.
5. 5
   The person who declines such an offer.
6. 6
   An impromptu guest used to fill in for another guest spot who is a no-show or who has cancelled last minute.