<p><strong>Noun</strong></p><ul><li>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).</li><li>the particles themselves.</li><li>an unexpected or incidental effect, outcome, or product: the psychological fallout of being obese.</li><li>effects; results: emotional fallout from a divorce.</li></ul>