safety net
noun
1- a net placed to catch an acrobat or similar performer in case of a fall（杂技表演者或类似的表演者用的）安全网。
1.1
- figurative a safeguard against possible hardship or adversity〈喻〉安全保障：
a safety net for workers who lose their jobs.
为失业工人提供的安全保障。