1 [uncountable and countable]
the failure of a relationship or system
He moved away after the breakdown of his marriage.
A sudden rise in oil prices could lead to a breakdown of the economy.
There has been a serious breakdown in relations between the two countries.
Family breakdown can lead to behavioural problems in children.
a serious medical condition in which someone becomes mentally ill and is unable to work or deal with ordinary situations in life:
I was worried he might have a breakdown if he carried on working so hard.
Two years ago he suffered a mental breakdown.
She had already had one nervous breakdown.
an occasion when a car or a piece of machinery breaks and stops working:
Always carry a phone with you in case you have a breakdown on the motorway.
a breakdown in the cooling system
a list of all the separate parts of something
Can you give us a breakdown of the figures?
the changing of a substance into other substances:
the breakdown of glucose in the body to release energy