defect

American  

[dee-fekt, dih-fekt, dih-fekt] / ˈdi fɛkt, dɪˈfɛkt, dɪˈfɛkt /

noun

• defects
  plural

1. a shortcoming, fault, or imperfection: a defect in a machine.

   a defect in an argument;

   a defect in a machine.

2. lack or want, especially of something essential to perfection or completeness; deficiency: a defect of action.

   a defect of common sense

   a defect of action.

3. Also called lattice defect.  Also called crystal defect,.  Crystallography. a discontinuity in the lattice of a crystal caused by missing or extra atoms or ions, or by dislocations.

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verb (used without object)

• defects,
  present (3rd person singular)
• defected,
  past participle,  past
• defecting
  present participle

1. to desert a cause, country, etc., especially in order to adopt another (often followed by from orto ).

   He defected from the U.S.S.R. to the West.

defect British  

noun

1. a lack of something necessary for completeness or perfection; shortcoming; deficiency

2. an imperfection, failing, or blemish

3. crystallog a local deviation from regularity in the crystal lattice of a solid See also point defect dislocation

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verb

1. (intr) to desert one's country, cause, allegiance, etc, esp in order to join the opposing forces

Synonym Usage

Defect, blemish, flaw refer to faults that detract from perfection. Defect is the general word for any kind of shortcoming or imperfection, whether literal or figurative: a defect in eyesight, in a plan. A blemish is usually a defect on a surface, which mars the appearance: a blemish on her cheek. Flaw is applied to a defect in quality, caused by imperfect structure (as in a diamond) or brought about during manufacture (as in texture of cloth, in clearness of glass, etc.).

Other Word Forms

Derived Forms

• defectibility
  noun
• defector
  noun
• predefect
  noun
• redefect
  verb (used without object)
• defectible
  adjective
• defectless
  adjective
• nondefecting
  adjective

Inflected Forms

Nouns

• defects
  plural

Participles

• defecting
  present
• defected
  past

Conjugated Forms

Present

• defect
  simple
• defects
  simple
• have defected
  perfect
• has defected
  perfect
• am defecting
  progressive
• are defecting
  progressive
• is defecting
  progressive
• have been defecting
  perfect progressive
• has been defecting
  perfect progressive

Past

• defected
  simple
• had defected
  perfect
• was defecting
  progressive
• were defecting
  progressive
• had been defecting
  perfect progressive

Future

• will defect
  simple
• will have defected
  perfect
• will be defecting
  progressive
• will have been defecting
  perfect progressive

Etymology

Origin of defect

First recorded in 1375–1425; late Middle English, from Latin dēfectus “failure, weakness,” equivalent to dēfec-, variant stem of dēficere “to run short, fail, weaken” ( see deficient) + -tus suffix of verb action

Explanation

A flaw in something is a defect. At certain stores you can buy clothes with slight defects. You have to be careful because the defect can be minor, like a missing button, or major, like sleeves of uneven lengths. In a person, a defect is an imperfection, which can manifest itself mentally or physically. If you are diagnosed with a heart defect, you will have to seek the advice of specialists. A hearing defect might leave your dad deaf in one ear. If you are becoming forgetful, you can joke that you are developing a mental defect, but if it continues, you'll probably want to have your head examined.

Example Sentences

See Examples For:

defect defects defected defecting

The serious birth defect affects one in 3,000 UK babies each year.

From BBC ● Aug. 3, 2026

Although the word defect may suggest a weakness, dislocations can help metals deform under extreme force instead of breaking apart.

From Science Daily ● Jul. 31, 2026

I was born with a heart defect, so I see a cardiologist every year to check up on it.

From MarketWatch ● Jul. 28, 2026

He later was diagnosed with a congenital heart defect but eventually was able to resume his basketball career.

From Los Angeles Times ● Jul. 17, 2026

She mended every defect she could find, both inside and out.

From "A Girl Named Disaster" by Nancy Farmer

Other transgressions there included urine contamination from rodents on food packaging and shelving, inadequate cleaning standards and structural defects allowing pest entry.

From BBC ● Jul. 21, 2026

In the worm's jaws, sharper changes in strain across tiny regions appear to increase the interlocking of defects within the atomic structure, producing the characteristic size effect.

From Science Daily ● Jul. 16, 2026

"Other schedule risks remain, including the detailed designs for the aircraft interiors, fabrication of the wire bundles, and rework to correct defects in structural modifications," the report said.

From Barron's ● Jul. 2, 2026

Factors include “older buildings that do not meet modern seismic standards, as well as hidden defects or structural vulnerabilities,” De Santis said.

From Los Angeles Times ● Jun. 27, 2026

I thought of Mother, and of the many times she’d told me that antibiotics poison the body, that they cause infertility and birth defects.

From "Educated" by Tara Westover

But last week, the replies were inundated with complaints that Letterboxd had defected to the corporate dark side, along with fearful pleas for the platform’s owners to reconsider.

From Salon ● Jul. 15, 2026

Jenrick is now a Reform MP, having defected from the Conservatives to Nigel Farage's party earlier this year.

From BBC ● Jul. 9, 2026

It was in 1990, while touring Europe with his hero Gillespie, that Sandoval finally defected from Cuba with his wife and son — and found the refuge he’d been seeking in the U.S.

From Los Angeles Times ● Jun. 12, 2026

Another senior RSF commander, al-Nour al-Guba, defected late last month and was received in Khartoum by army chief Abdel Fattah al-Burhan.

From Barron's ● May 5, 2026

Later, Celia would learn with sadness that the girl had defected while on tour in Oaxaca and was playing a psychotic housewife on a popular Mexican novela.

From "Dreaming in Cuban" by Cristina García

It started with Navratilova, a record nine-time singles champion at the All England Club, who remained an inspiration to those back in her homeland after defecting from communist Czechoslovakia to the United States in 1975.

From BBC ● Jul. 11, 2026

At the dinner, I tried to get a sense if there were more women like Smith—sweet, older Christian Alabamians—snapping and defecting to the left.

From Slate ● May 4, 2026

The defecting lawmakers are making it heard that their decision wasn’t taken lightly.

From Salon ● Jan. 9, 2026

Suddenly, Golding had to do more than scramble to hire new staff, keep recruits from defecting, and convince players not to transfer to other schools.

From The Wall Street Journal ● Dec. 19, 2025

Internal strife in Parthia had its leaders distracted and its allies defecting.

From "Sterling Biographies®: Cleopatra: Egypt's Last and Greatest Queen" by Susan Blackaby

Related Words

• bug
• crack
• deficiency
• deformity
• error
• fault
• flaw
• glitch
• injury
• irregularity
• lack
• mistake
• shortage
• shortcoming
• weakness