[ noun dee-fekt, dih-fekt; verb dih-fekt ]
See synonyms for: defectdefecteddefectingdefects on

  1. a shortcoming, fault, or imperfection: 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 common sense;a defect of action.

  1. Also called crys·tal de·fect, lattice defect. Crystallography. a discontinuity in the lattice of a crystal caused by missing or extra atoms or ions, or by dislocations.

verb (used without object)
  1. to desert a cause, country, etc., especially in order to adopt another (often followed by from or to): He defected from the U.S.S.R. to the West.

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

synonym study For defect

1. 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 words from defect

  • de·fect·i·ble, adjective
  • de·fect·i·bil·i·ty [dih-fek-tuh-bil-i-tee], /dɪˌfɛk təˈbɪl ɪ ti/, noun
  • de·fect·less, adjective
  • non·de·fect·ing, adjective
  • pre·de·fect, noun
  • re·de·fect, verb (used without object)

Words Nearby defect Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use defect in a sentence

British Dictionary definitions for defect


noun(dɪˈfɛkt, ˈdiːfɛkt)
  1. a lack of something necessary for completeness or perfection; shortcoming; deficiency

  2. an imperfection, failing, or blemish

  1. crystallog a local deviation from regularity in the crystal lattice of a solid: See also point defect, dislocation (def. 3)

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

Origin of defect

C15: from Latin dēfectus, from dēficere to forsake, fail; see deficient

Derived forms of defect

  • defector, noun

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012