de·​fec·​tive | \ di-ˈfek-tiv How to pronounce defective (audio) \

Definition of defective

 (Entry 1 of 2)

1a : having a defect or flaw : imperfect in form, structure, or function replaced a defective light switch products manufactured with defective materials defective intestinal absorption a defective gene
b dated, now offensive : having a physical or mental impairment
2 grammar : lacking one or more of the usual forms of inflection (see inflection sense 2) Must is a defective verb.



Definition of defective (Entry 2 of 2)

1 : something that is imperfect in form, structure, or function … if we examine 18 items off the production line, we may be interested in the number of defectives we observe in the sample of size 18.— Lloyd Jaisingh
2 dated, now offensive : a person having a physical or mental impairment

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Other Words from defective


defectively adverb
defectiveness noun

Synonyms & Antonyms for defective

Synonyms: Adjective

Antonyms: Adjective

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Examples of defective in a Sentence

Adjective This computer is defective. I want my money back. The disease is caused by a defective gene.
Recent Examples on the Web: Adjective Gene therapy, which replaces defective genes, promises to deliver one-time treatment for inherited diseases. Joseph Walker, WSJ, 1 Oct. 2021 Stall concluded the defective foundations were caused by any one or a combination of factors, including incorrect soil preparation, incorrect concrete mix, incorrect placement of reinforcement steel or poor workmanship. Patrick Danner, San Antonio Express-News, 1 Oct. 2021 These include many combinations of defective proteins. Mark Johnson, Milwaukee Journal Sentinel, 30 Sep. 2021 The town’s council terminated the contract of Reef Parking because of defective parking meters and the need for new ideas. From Usa Today Network And Wire Reports, USA TODAY, 30 Sep. 2021 It was needed to fix a defective unit badly in need of playmakers. Calvin Watkins, Dallas News, 29 Sep. 2021 Drivers may have been responsible, or defective vehicles, and their makers, liable. William Thornton |, al, 20 Sep. 2021 The Detroit automaker plans to start replacing the defective batteries in October. David Welch, Fortune, 20 Sep. 2021 People who are defective in generating an interferon response have a far greater chance of being hospitalized and falling ill than those who aren’t. William A. Haseltine, Forbes, 20 Sep. 2021 Recent Examples on the Web: Noun After two replacement phones (one defective, the next meant for another customer and locked) and 15 different Apple customer service representatives, Holland, a publicist in Wilmington, N.C., searched online for Jobs’s email address. Washington Post, 23 Feb. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'defective.' 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 defective


14th century, in the meaning defined at sense 1a


1562, in the meaning defined at sense 1

History and Etymology for defective


Middle English defectif, defectyve "lacking, faulty, of poor quality," borrowed from Anglo-French defectif, borrowed from Late Latin dēfectīvus "lacking an inflectional form, imperfect, faulty," from Latin dēfectus, past participle of dēficere "to be lacking, run short, fail" + -īvus -ive — more at deficient


derivative of defective entry 1

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Time Traveler for defective

Time Traveler

The first known use of defective was in the 14th century

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Dictionary Entries Near defective



defective delinquent

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Last Updated

14 Oct 2021

Cite this Entry

“Defective.” Dictionary, Merriam-Webster, Accessed 20 Oct. 2021.

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More Definitions for defective



English Language Learners Definition of defective

: having a problem or fault that prevents something from working correctly : having a defect or flaw


de·​fec·​tive | \ di-ˈfek-tiv How to pronounce defective (audio) \

Kids Definition of defective

: having a defect or flaw The car's brakes were defective.


de·​fec·​tive | \ di-ˈfek-tiv How to pronounce defective (audio) \

Medical Definition of defective

: falling below the norm in structure or function a defective heart valve

Other Words from defective

defectiveness \ -​nəs How to pronounce defective (audio) \ noun

More from Merriam-Webster on defective

Nglish: Translation of defective for Spanish Speakers

Britannica English: Translation of defective for Arabic Speakers


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