Definition of fault:
a wrong action attributable to bad judgment or ignorance or inattention; "he made a bad mistake"; "she was quick to point out my errors"; "I could understand his English in spite of his grammatical faults"
an imperfection in an object or machine; "a flaw caused the crystal to shatter"; "if there are any defects you should send it back to the manufacturer"
the quality of being inadequate or falling short of perfection; "they discussed the merits and demerits of her novel"; "he knew his own faults much better than she did"
(geology) a crack in the earth's crust resulting from the displacement of one side with respect to the other; "they built it right over a geological fault"; "he studied the faulting of the earth's crust"
(electronics) equipment failure attributable to some defect in a circuit (loose connection or insulation failure or short circuit etc.); "it took much longer to find the fault than to fix it"
responsibility for a bad situation or event; "it was John's fault"
(sports) a serve that is illegal (e.g., that lands outside the prescribed area); "he served too many double faults"
put or pin the blame on