This use of 'failed' means that someone did not pass or complete a task or test. It shows lack of success in something.
She failed the math exam yesterday.
He failed to open the door on time.
'Failed' can describe a machine or part that stopped working or did not function. It means the machine is broken or does not work as expected.
The engine failed during the trip.
My phone failed to charge last night.
Here, 'failed' is used when a person or group does not do what they said they would. It means they did not fulfill a duty or promise.
He failed to keep his promise.
The company failed to deliver on time.
Used especially in medical or technical contexts, this means an important organ or system stopped working or working correctly.
His heart failed during the marathon.
The system failed because of a power cut.
'Failed' is the past form of the verb 'fail'. It shows that the action of not succeeding happened in the past.
I failed the test yesterday.
They failed to arrive on time.
