What does FAIL mean?

verb

1. fail to do something; leave something undone“She failed to notice that her child was no longer in his crib”
2. be unsuccessful“Where do today's public schools fail?”
3. disappoint, prove undependable to; abandon, forsake“His sense of smell failed him this time”
4. stop operating or functioning“The engine finally went”
5. be unable“I fail to understand your motives”
6. judge unacceptable“The teacher failed six students”
7. fail to get a passing grade“She studied hard but failed nevertheless”
8. fall short in what is expected“She failed in her obligations as a good daughter-in-law”