noun

fault

A defect that makes something fall short of proper operation or standards.

A fault in the wiring keeps the lights from working.

Etymology

The source word meant a lack or failing. A fault is something missing or defective that prevents a thing from meeting its expected standard.

More examples

  • The inspector finds several faults in the building's design.
  • Impatience is one of her few faults.
  • In tennis, a serve that lands outside the service box is a fault.

Forms

fault · faults

faulty adjective — Having defects or failing to work properly.

faultless adjective — Free from defects, errors, or imperfections.

Similar words

defect
Emphasizes a specific problem in construction, structure, or quality.
flaw
Can describe an imperfection that does not prevent normal operation.
malfunction
Specifically describes equipment or a system failing to work properly.