fault

1 fault /ˈfɑːlt/ noun
plural faults
1 fault
/ˈfɑːlt/
noun
plural faults
Britannica Dictionary definition of FAULT
1 
[count]
a  : a bad quality or part of someone's character : a weakness in character
b  : a problem or bad part that prevents something from being perfect : a flaw or defect
2 
[noncount] : responsibility for a problem, mistake, bad situation, etc.
3 
[count] tennis : a mistake that results in a bad serve — see also double fault
4 
[count] geology : a break in the Earth's crust

at fault

: deserving blame for something bad : responsible

find fault

— see 1find

to a fault

: to a great or excessive degree

— faultless

/ˈfɑːltləs/ adjective

— faultlessness

noun [noncount]
2 fault /ˈfɑːlt/ verb
faults; faulted; faulting
2 fault
/ˈfɑːlt/
verb
faults; faulted; faulting
Britannica Dictionary definition of FAULT
[+ object]
1 
: to criticize (something)
2 
: to blame or criticize (someone)