fail
Americanverb (used without object)
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to fall short of success or achievement in something expected, attempted, desired, or approved.
The experiment failed because of poor planning.
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to receive less than the passing grade or mark in an examination, class, or course of study.
He failed in history.
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to be or become deficient or lacking; be insufficient or absent; fall short.
Our supplies failed.
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to dwindle, pass, or die away.
The flowers failed for lack of rain.
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to lose strength or vigor; become weak.
His health failed after the operation.
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to become unable to meet or pay debts or business obligations; become insolvent or bankrupt.
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(of a building member, structure, machine part, etc.) to break, bend, crush, or be otherwise destroyed or made useless because of an excessive load.
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to stop functioning or operating.
The electricity failed during the storm.
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Slang.
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to make an embarrassing or humorous mistake, be in a humiliating situation, etc., and be subject to ridicule.
Showed up late to the wedding? You fail!
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to be embarrassingly incompetent, stupid, etc..
She fails at life. I just failed at walking and fell on my face.
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to be bad or of inferior quality.
The play is terrible—even the music fails.
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verb (used with object)
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to be unsuccessful in the performance or completion of.
He failed to do his duty.
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(of some expected or usual resource) to prove of no use or help to.
His friends failed him. Words failed her.
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to receive less than a passing grade or mark in.
He failed history.
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to declare (a person) unsuccessful in a test, course of study, etc.; give less than a passing grade to.
The professor failed him in history.
noun
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Slang.
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an embarrassing or humorous mistake, humiliating situation, etc., that is subject to ridicule and given an exaggerated importance.
Their app update is a massive fail.
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the condition or quality resulting from having failed in this way.
His online post is full of fail.
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a person who fails in this way.
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Stock Exchange.
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a stockbroker's inability to deliver or receive security within the required time after sale or purchase.
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such an undelivered security.
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Obsolete. failure as to performance, occurrence, etc.
interjection
adjective
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unsuccessful; failed.
a totally fail policy.
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Slang.
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of or noting an embarrassing or humorous mistake, humiliating situation, etc..
the top 100 funniest fail photos on the internet.
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embarrassingly incompetent, stupid, etc.
Why am I so fail?
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very bad or of inferior quality.
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idioms
verb
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to be unsuccessful in an attempt (at something or to do something)
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(intr) to stop operating or working properly
the steering failed suddenly
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to judge or be judged as being below the officially accepted standard required for success in (a course, examination, etc)
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(tr) to prove disappointing, undependable, or useless to (someone)
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(tr) to neglect or be unable (to do something)
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(intr) to prove partly or completely insufficient in quantity, duration, or extent
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(intr) to weaken; fade away
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(intr) to go bankrupt or become insolvent
noun
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a failure to attain the required standard, as in an examination
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definitely; with certainty
noun
Other Word Forms
Derived Forms
Inflected Forms
Participles
Conjugated Forms
Present
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failsimple
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failssimple
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have failedperfect
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has failedperfect
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am failingprogressive
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are failingprogressive
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is failingprogressive
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have been failingperfect progressive
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has been failingperfect progressive
Past
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failedsimple
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had failedperfect
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was failingprogressive
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were failingprogressive
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had been failingperfect progressive
Future
Etymology
Origin of fail
First recorded in 1175–1225; Middle English failen, from Anglo-French, Old French faillir, from unattested Vulgar Latin fallīre, for Latin fallere “to disappoint, deceive”
Explanation
The verb fail describes something that stops working, like brakes in a car that fail, or is found to be unacceptable, like restaurants that fail their inspection for cleanliness. The verb fail comes from the Old French word faillir, meaning “be lacking,” “miss,” or “not succeed.” You can fail an exam, which means you didn't get at least a minimum number of points to pass. You can fail to live up to your potential, meaning you aren't able to meet expectations. When businesses fail, it means financial problems force them to close.
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
And should the new technology fail to match those high hopes, the economic consequences will likely be felt far beyond the U.S.
From The Wall Street Journal ● Jul. 23, 2026
For-profit colleges, which have long faced criticism for saddling students with debt for little benefit, have the highest expected fail rate.
From Los Angeles Times ● Jul. 22, 2026
Perhaps the same will be true with “Obsession”; Curry Barker’s copycats will try and fail to interpret the trials of dating when personality is a facade, and I’ll be left eating crow.
From Salon ● Jul. 22, 2026
If the discharge flow at the time of the test is insufficient to take a sample, it is not regarded as a fail, and no samples are taken for the rest of the testing period.
From BBC ● Jul. 22, 2026
“They thought they were being followed,” said Fernande Olivier, Picasso’s partner, who’d just watched them fail to play cards.
From "The Mona Lisa Vanishes" by Nicholas Day
The refreshing sight of the women teaming up against Falstaff never fails to amuse.
From Los Angeles Times ● Jul. 23, 2026
Instead of responding only after a treatment fails, doctors may eventually be able to anticipate resistance and act before the tumor regains strength.
From Science Daily ● Jul. 22, 2026
It is, of course, a natural limitation of the defense of the Great Books, as a genre, that the discourse fails to live up to the actual experience of reading any one of those books.
From The Wall Street Journal ● Jul. 19, 2026
Hideya Kawanishi, a professor at Nagoya University and expert in Japan's emperor system, told AFP that the new bill "fails to reflect public opinion".
From Barron's ● Jul. 17, 2026
What if my brain fails me once again?
From "I Am Not Your Perfect Mexican Daughter" by Erika L. Sánchez
The administration announced levies of 10% for countries that have bans on forced labor and 12.5% on those that have failed to adopt such prohibitions.
From MarketWatch ● Jul. 23, 2026
“At a time when campuses face budget constraints, staffing shortages, and growing student needs, CSU resources must not be used to provide a financial cushion for failed leadership,” Jones said in a news release.
From Los Angeles Times ● Jul. 23, 2026
In the second quarter, IBM failed to close “tens of deals,” which led to the disappointing results, James Kavanaugh, IBM’s chief financial officer, said in an interview with The Wall Street Journal.
From The Wall Street Journal ● Jul. 22, 2026
The group claims the Home Office failed to exercise its powers with the openness required.
From BBC ● Jul. 22, 2026
The last time they’d shouted at each other, it was over Molly’s failed attempts to catch and kill the Son of Sam, and that had been in the ’70s.
From "Night Owls" by A.R. Vishny
The Dodgers were widely criticized by fans for failing to speak out at the time.
From Barron's ● Jul. 23, 2026
Greer’s office had concluded a Section 301 investigation last month and accused 60 trading partners of failing to prevent the importation of goods produced with forced labor.
From MarketWatch ● Jul. 23, 2026
The paper says senior economists are warning that the new prime minister will need to raise taxes, or else risk failing to deliver on his raft of "bolder policy pledges".
From BBC ● Jul. 22, 2026
After failing to do well on the retest, she has felt dejected, he said.
From The Wall Street Journal ● Jul. 20, 2026
They’re fighting and failing to keep straight faces.
From "Kwame Crashes the Underworld" by Craig Kofi Farmer
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.