de·​fect | \ ˈdē-ˌfekt How to pronounce defect (audio) , di-ˈfekt How to pronounce defect (audio) \

Essential Meaning of defect

1 : a physical problem that causes something to be less valuable, effective, healthy, etc. This small defect [=flaw] greatly reduces the diamond's value. They examine their products for defects. See More Examplesa minor/major defect She was born with a heart defect. a birth defect [=a physical problem that someone is born with]Hide
2 : something that causes weakness or failure We had to point out the defect [=flaw] in their logic. Vanity and pride were his two worst character defects.

Full Definition of defect

 (Entry 1 of 2)

1 : an imperfection or abnormality that impairs quality, function, or utility : shortcoming, flaw carefully inspect a tire for defects examined the porcelain for defects a moral defect in his nature neural tube defects defects of metabolism
2 chemistry : an imperfection (such as a vacancy or an unlike atom) in a crystal lattice (see lattice sense 2)


de·​fect | \ di-ˈfekt How to pronounce defect (audio) \
defected; defecting; defects

Definition of defect (Entry 2 of 2)

intransitive verb

1 : to forsake one cause, party, or nation for another often because of a change in ideology a former KGB agent who defected to America
2 : to leave one situation (such as a job) often to go over to a rival the reporter defected to another network

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Other Words from defect


defector \ di-​ˈfek-​tər How to pronounce defect (audio) \ noun

Examples of defect in a Sentence

Noun They examine their products for defects. She was born with a heart defect. Vanity and pride were his two worst character defects. Verb The Russian scholar defected in 1979. She defected from the conservative party. He defected to the West before the war began. The reporter defected to another TV network.
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Recent Examples on the Web: Noun But the testing revealed the baby had high markers for Down syndrome, and later scans revealed a heart defect that may require immediate surgery. Holly V. Hays, The Indianapolis Star, 24 Sep. 2021 The 51-page report from the Bureau of Alcohol, Tobacco, Firearms and Explosives, released Tuesday, ruled out other possible causes, such as an equipment defect, for the June 30 blast in South Los Angeles. Stefanie Dazio, USA TODAY, 15 Sep. 2021 The solution to their genetic defect problem, experts say, lies much closer to home. Craig Pittman, Scientific American, 1 Sep. 2021 As jury selection began Tuesday ahead of opening arguments next week, Holmes has laid the groundwork for an unusual mental defect defense. Washington Post, 31 Aug. 2021 Louise first tended to Alice, who spent years in the hospital and on crutches for a congenital skeletal defect. Cheryl Hall, Dallas News, 22 Aug. 2021 Małysa, whose heart defect causes his blood pressure to skyrocket and damage the arteries in his lungs and in the heart, is currently at home in southern Poland and receiving hospice care, the page reports. NBC News, 18 Aug. 2021 This week saw Apple confirm a manufacturing defect with the iPhone 12 and iPhone 12 Pro handsets manufactured between October 2020 and April 2021. Ewan Spence, Forbes, 3 Sep. 2021 Augustin was acquitted by reason of mental disease or defect in June., 26 Aug. 2021 Recent Examples on the Web: Verb On the other hand, the Taliban fear that any such concessions could alienate their own hard-line foot soldiers, making some of them defect to Islamic State, which is also known as Daesh. Saeed Shah, WSJ, 8 Oct. 2021 The company has been hit with falling sales and declining foot traffic in recent years as shoppers defect to competitors such as Target and Amazon, which carry much of the same household basics that Bed Bath & Beyond sells. Jordan Valinsky, CNN, 30 Sep. 2021 Cuban officials also blamed the US for restrictions that force Cuban players to defect in order to play in the Major Leagues. Patrick Oppmann, CNN, 3 Oct. 2021 If enough progressives defect, there will likely not be enough Republican votes to pass it. Charlotte Alter, Time, 29 Sep. 2021 To pull off a win, recall backers must hope a significant number of Democrats defect from Newsom and vote in favor of the recall. Seema Mehta, Los Angeles Times, 8 Sep. 2021 During the opening ceremony at the Indianapolis Motor Speedway, where the crowd approached 80,000, a plane chartered by anti-Castro activists flew a banner urging Cuban athletes to defect. David Woods, The Indianapolis Star, 18 Mar. 2021 Voters who make a mistake — like forgetting to sign a mail ballot certificate or omitting residency information, or if their signature is questioned — may fix that defect to ensure their ballot counts. Adam Brewster, CBS News, 7 Sep. 2021 During the Taliban's insurgency, Muttaqi chaired the Invitation and Guidance Commission, which sought to encourage government officials and others to defect to the group. NBC News, 7 Sep. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'defect.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of defect


15th century, in the meaning defined at sense 1


1596, in the meaning defined at sense 1

History and Etymology for defect


Middle English, borrowed from Latin dēfectus "failure, absence, lack, weakness," from dēficere "to be lacking, run short, weaken, fail" + -tus, suffix of action nouns — more at deficient


borrowed from Latin dēfectus, past participle of dēficere "to be lacking, fail, become disaffected, go over (to the side of an opponent)" — more at deficient

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The first known use of defect was in the 15th century

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Last Updated

11 Oct 2021

Cite this Entry

“Defect.” Dictionary, Merriam-Webster, Accessed 25 Oct. 2021.

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More Definitions for defect


de·​fect | \ ˈdē-ˌfekt How to pronounce defect (audio) , di-ˈfekt \

Kids Definition of defect

1 : something that makes a thing imperfect : flaw A slight defect lowered the diamond's value.
2 : a lack of something needed for perfection Doctors can correct the hearing defect.


de·​fect | \ ˈdē-ˌfekt How to pronounce defect (audio) , di-ˈ How to pronounce defect (audio) \

Medical Definition of defect

: a lack or deficiency of something necessary for adequacy in form or function a hearing defect


de·​fect | \ ˈdē-ˌfekt, di-ˈfekt How to pronounce defect (audio) \

Legal Definition of defect

: something or a lack of something that results in incompleteness, inadequacy, or imperfection: as
a : a flaw in something (as a product) especially that creates an unreasonable risk of harm in its normal use — see also latent defect
b : an error or omission in a court document (as an indictment or pleading)
c : some imperfection in the chain of title to property that makes the title unmarketable

Other Words from defect

defective \ di-​ˈfek-​tiv How to pronounce defect (audio) \ adjective
defectively adverb
defectiveness noun

More from Merriam-Webster on defect

Nglish: Translation of defect for Spanish Speakers

Britannica English: Translation of defect for Arabic Speakers Encyclopedia article about defect


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