Definition of "fallback"

An act of falling back.  examples

A backup plan or contingency strategy; an alternative which can be used if something goes wrong with the main plan; a recourse.  examples

(construction) A reduction in bitumen softening point, sometimes called refluxing or overheating, in a relatively closed container.  examples

Pulverised material that falls back to earth after a nuclear explosion; fallout.  quotations  examples

That can be resorted to as a fallback.  examples

Misspelling of fall back.  examples