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, 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 pilots remain in control of the airplane," Bedford said of the new software defect.

From Barron's ● Sep. 28, 2026

If an aircraft crashes, we focus on finding the engineering defect, correcting it, and enforcing established liability standards for the damage created.

From The Wall Street Journal ● Sep. 21, 2026

Rolfe told the BBC at the time he would not resign, saying the software defect was "very, very obscure".

From BBC ● Sep. 21, 2026

The contract explicitly provided that she would terminate the pregnancy if the fetus had a serious birth defect and the intended parents requested an abortion.

From Slate ● Sep. 17, 2026

Including my sister Doreena who never lifted a royal finger growing up because she had the heart defect that we later found out was a fly on the X-ray machine.

From "The Help" by Kathryn Stockett

But the report also identified improperly roofing defects, low water pressure and what inspectors described as "exceptionally poor" installation of the gas meter cabinet and gas pipe.

From BBC ● Sep. 26, 2026

This is not the first case in which a surrogate has refused to terminate a pregnancy after the intended parents learned that the fetus had serious birth defects.

From Slate ● Sep. 17, 2026

To investigate the system, the researchers combined genetic information from people with congenital heart defects with experiments involving zebrafish, human cells and mouse stem cells.

From Science Daily ● Sep. 15, 2026

He also acknowledged that if the U.S. slows AI development alongside China, and the latter defects, it could lead to China’s geopolitical dominance.

From MarketWatch ● Sep. 14, 2026

In 2006, some seven hundred new mothers found out that doctors had taken their placentas without consent to test for abnormalities that might help the hospital defend itself against future lawsuits over birth defects.

From "The Immortal Life of Henrietta Lacks" by Rebecca Skloot

The book’s title refers to the Soviet agent Oleg Lyalin, a relatively low-level but irrepressibly ambitious KGB operative who defected to Britain in 1971.

From The Wall Street Journal ● Sep. 20, 2026

Kendall had been a key backer of Democrat Andrew Jackson in the 1828 election, having defected from Henry Clay’s Whigs.

From Slate ● Sep. 4, 2026

Arabs within the SDF's ranks also defected en masse after Sharaa's army took control of two previously Kurdish-held provinces, Raqa and Deir Ezzor, leaving them at half their strength, according to Syria specialist Fabrice Balanche.

From Barron's ● Aug. 25, 2026

Few people understood this effort better than Ladislav Bittman, a senior propagandist in the Czechoslovakian intelligence service who defected to the West in 1968.

From The Wall Street Journal ● Aug. 12, 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

Then came the next bombshell as it emerged that Reform MS for Pen-y-bont Bro Morgannwg Sarah Cooper-Lesadd was defecting to Plaid Cymru.

From BBC ● Sep. 20, 2026

He led Barnet Council from 2019 until 2022 before defecting to Reform in June 2025.

From BBC ● Sep. 15, 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

Common sense told him that telling lies and defecting from duty were sins.

From "Catch-22" by Joseph Heller

Related Words

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