defect

American  

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

noun

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)

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

Related Words

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

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

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

Traditional product liability demands a defect in the product or its labeling.

From The Wall Street Journal • May 5, 2026

Regulators on Wednesday officially classified this as a Class I Recall, with 476 serious injuries potentially linked to the defect.

From Barron's • Apr. 30, 2026

The former five-star recruit out of Sierra Canyon High is still growing into his career, especially after surgery for a congenital heart defect derailed his brief college experience.

From Los Angeles Times • Apr. 25, 2026

In most industries, a high defect rate is a problem to fix because it wastes time and money.

From MarketWatch • Apr. 22, 2026

“There is, I believe, in every disposition a tendency to some particular evil—a natural defect, which not even the best education can overcome.”

From "Pride and Prejudice" by Jane Austen

Related Words

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