A fault is an error caused by ignorance, bad judgment or inattention. If you're a passenger, it might be your fault that your friend missed the exit, if you were supposed to be watching for it, not sleeping.

Fault can mean "blame" — as a noun or verb. If you say, "It's my fault," you accept the blame. Well, they can't fault you for telling the truth, at least. A fault can be a shortcoming — everyone has faults because no one is perfect — or a crack in the earth's crust, like the San Andreas Fault. In sports like tennis, a fault is an illegal hit of the ball, usually when it lands outside the playing area.

Primary Meanings of fault

an imperfection in an object or machine
responsibility for a bad situation or event
put or pin the blame on
(geology) a crack in the earth's crust resulting from the displacement of one side with respect to the other
Full Definitions of fault

n an imperfection in an object or machine

defect, flaw
a flaw on a surface resulting when an applied substance does not adhere (as an air bubble in a coat of paint)
bug, glitch
a fault or defect in a computer program, system, or machine
a fault
Type of:
imperfection, imperfectness
the state or an instance of being imperfect

n the quality of being inadequate or falling short of perfection

“he knew his own faults much better than she did”
merit, virtue
any admirable quality or attribute
Type of:
the quality that renders something desirable or valuable or useful

n a wrong action attributable to bad judgment or ignorance or inattention

“I could understand his English in spite of his grammatical faults
error, mistake
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blot, smear, smirch, spot, stain
an act that brings discredit to the person who does it
confusion, mix-up
a mistake that results from taking one thing to be another
the mistake of incurring liability or blame
miscalculation, misestimation, misreckoning
a mistake in calculating
the mistake of misrepresenting the facts
miscue, parapraxis, slip, slip-up
a minor inadvertent mistake usually observed in speech or writing or in small accidents or memory lapses etc.
(sport) the mistake of occupying an illegal position on the playing field (in football, soccer, ice hockey, field hockey, etc.)
lapse, oversight
a mistake resulting from inattention
omission, skip
a mistake resulting from neglect
bloomer, blooper, blunder, boo-boo, botch, bungle, flub, foul-up, pratfall
an embarrassing mistake
balls-up, ballup, cockup, mess-up
something badly botched or muddled
betise, folly, foolishness, imbecility, stupidity
a stupid mistake
renege, revoke
the mistake of not following suit when able to do so
an unexpected omission
the momentary juggling of a batted or thrown baseball
backfire, boomerang
a miscalculation that recoils on its maker
rounding, rounding error
(mathematics) a miscalculation that results from rounding off numbers to a convenient number of decimals
truncation error
(mathematics) a miscalculation that results from cutting off a numerical calculation before it is finished
Freudian slip
a slip-up that (according to Sigmund Freud) results from the operation of unconscious wishes or conflicts and can reveal unconscious processes in normal healthy individuals
a blunder that makes you look ridiculous; used in the phrase `make a spectacle of' yourself
a serious and ludicrous blunder
fumble, muff
(sports) dropping the ball
a blunder (especially an actor's forgetting the lines)
faux pas, gaffe, gaucherie, slip, solecism
a socially awkward or tactless act
a glaring blunder
a conspicuous mistake whose effects seem to reverberate
misstep, stumble, trip, trip-up
an unintentional but embarrassing blunder
Type of:
nonaccomplishment, nonachievement
an act that does not achieve its intended goal

n (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”
Type of:
breakdown, equipment failure
a cessation of normal operation

n (sports) a serve that is illegal (e.g., that lands outside the prescribed area)

“he served too many double faults
double fault
(tennis) two successive faults in serving resulting in the loss of the point
a fault that occurs when the server in tennis fails to keep both feet behind the baseline
Type of:
serve, service
(sports) a stroke that puts the ball in play

n responsibility for a bad situation or event

“it was John's fault
Type of:
responsibility, responsibleness
a form of trustworthiness; the trait of being answerable to someone for something or being responsible for one's conduct

v put or pin the blame on

absolve, free, justify
excuse or free from blame
Type of:
accuse, charge
blame for, make a claim of wrongdoing or misbehavior against

n (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
break, faulting, fracture, geological fault, shift
Denali Fault
a major open geological fault in Alaska
San Andreas Fault
a major geological fault in California; runs from San Diego to San Francisco; the source of serious earthquakes
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inclined fault
a geological fault in which one side is above the other
strike-slip fault
a geological fault in which one of the adjacent surfaces appears to have moved horizontally
common fault, gravity fault, normal fault
an inclined fault in which the hanging wall appears to have slipped downward relative to the footwall
overthrust fault, reverse fault, thrust fault
a geological fault in which the upper side appears to have been pushed upward by compression
Type of:
cleft, crack, crevice, fissure, scissure
a long narrow opening

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