(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"
(sports) a serve that is illegal (e.g., that lands outside the prescribed area)
"he served too many double faults"
A defect; something that detracts from perfection.
"The car ran perfectly until a small scratch on the bumper revealed an old paint job, which was the only fault in its otherwise pristine condition."
In plain English: A fault is a mistake or something that goes wrong.
"The car broke down due to mechanical fault."
Usage: Use "fault" to refer to a specific defect or shortcoming in an object, system, or performance that prevents it from being perfect. Avoid using it to describe moral blame when you simply mean the person responsible for an error.
To criticize, blame or find fault with something or someone.
"The manager spent the entire meeting finding fault with every minor detail of our presentation."
In plain English: To fault something is to criticize it or point out that it has a problem.
"The storm caused the power to fault and shut down the entire neighborhood grid."
Usage: Use "fault" as a verb when you are criticizing someone's actions or pointing out their errors. Do not use it to mean being at fault for an accident; instead, say that the person is "at fault."
The word "fault" comes from the Vulgar Latin fallita, meaning "shortcoming," which entered English through Anglo-Norman and Old French. It eventually replaced native Middle English words like schuld and lac that originally carried similar meanings of blame or lack.