a sudden failure in the way something works, so that it cannot continue
business/system/idea etc[singular, uncountable]
the collapse of the Soviet Union
the threat of economic collapse
His business was in danger of collapse.
when something suddenly falls down:
the collapse of an apartment building during the earthquake
The ancient abbey was in imminent danger of collapse.
when someone suddenly falls down or becomes unconscious because of an illness or injury:
The president said he was fine after his collapse yesterday.
She suffered a collapse under anaesthetic.
a sudden decrease in the value of something:
the collapse of the stock market
a collapse in the value of pensions