Definition of fall back

The term "fall back" typically refers to a strategy or action that is taken as a backup or alternate plan when the initial plan fails or becomes ineffective. The origin of the phrase can be traced back to the military tactic known as a retreat or withdrawal, where soldiers would "fall back" to a more secure position. In the late 1800s, the phrase "fall back" started being used in non-military contexts to describe a contingency plan or backup solution. It was often used to describe the actions that a company would take if its primary system or process failed, such as falling back to a manual system or using a backup generator. During World War II, the phrase "fall back" gained widespread popularity as part of the military lexicon. It was used to denote a strategic retreat that was done carefully and methodically, as opposed to an uncontrolled and chaotic rout. This usage of the phrase crystallized in popular culture, and it has since become a well-known idiom in both military and civilian contexts.