The phrasal verb "fall back" is more commonly used in informal speech rather than formal writing or communications. It generally means to retreat or to move back to a previous position. This term is often employed in military contexts to describe a strategic withdrawal to a safer or more advantageous position. Additionally, "fall back" can be used figuratively to describe relying on something as a backup plan, particularly when an initial plan fails — for example, 'If my career in music doesn’t succeed, I'll fall back on my degree in accounting.' It is less likely to appear in formal documents, unless describing tactical maneuvers within a financial or strategic report.
B2
UpperIntermediate
1. To retreat or move backwards in order to regroup or reposition oneself.
The army was forced to fall back to a defensible position after being outnumbered by the enemy.
As the storm approached, we decided to fall back and find shelter in a nearby building.
2. To decrease in severity or intensity after a strong or intense activity.
After the initial confrontation, the noise in the room started to fall back as people calmed down.
Once the major sale event ended, the shop's business fell back to normal levels.
3. To rely on an alternative plan or position when the initial one fails.
We had to fall back on our savings when my husband lost his job.
In case the presentation equipment fails, we can always fall back on printed handouts.