What is the meaning of the word "fault"?

Definitions:

a crack in the earth's crust resulting from the displacement of one side with respect to the other noun
- They built it right over a geological fault.
in electronics, equipment failure attributable to some defect in a circuit, such as a loose connection, insulation failure or short circuit noun
- It took much longer to find the fault than to fix it.
in tennis, a serve that is illegal, e.g one that lands outside the prescribed area noun
- They served too many double faults.
responsibility for a bad situation or event noun
- The mistake was completely my fault.
the quality of being inadequate or falling short of perfection noun
- I have a number of faults in my personality.
to put or pin the blame on verb
- I couldn't fault the intern for the mistakes that had been made.