An act of falling back.
Pulverised material that falls back to earth after a nuclear explosion; fallout.
A backup plan or contingency strategy; an alternative which can be used if something goes wrong with the main plan; a recourse.
A reduction in bitumen softening point, sometimes called refluxing or overheating, in a relatively closed container.
That can be resorted to as a fallback.
Any journey downwards or fall.
A retreat, especially a military one.
A journey from the interior of a country to the coast.
The presence of downward (drainage or katabatic) winds.
A mytheme or trope in which the hero embarks on a journey to the underworld.