defective
Americanadjective
-
Sometimes defected having a defect or flaw; faulty; imperfect.
a defective machine.
- Synonyms:
- deficient, incomplete
-
Psychology. characterized by subnormal intelligence or behavior.
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Grammar. (of an inflected word or its inflection) lacking one or more of the inflected forms proper to most words of the same class in the language, as English must, which occurs only in the present tense.
noun
adjective
-
having a defect or flaw; imperfect; faulty
-
(of a person) below the usual standard or level, esp in intelligence
-
grammar (of a word) lacking the full range of inflections characteristic of its form class, as for example must, which has no past tense
Other Word Forms
Etymology
Origin of defective
First recorded in 1375–1425; from Late Latin dēfectīvus, equivalent to dēfectus ( see defect) + -īvus -ive; replacing Middle English defectif, from Middle French, from Late Latin, as above
Explanation
Something that's defective doesn't work quite right, because it's damaged in some way. Your defective car probably won't make it all the way to California from New York. Defective things are broken or flawed. A defective blender won't mix your morning smoothie the way you want it to, and a defective law doesn't serve the people it's meant to protect. A very old-fashioned meaning of defective, which is considered quite offensive today, is "mentally ill" or "mentally handicapped." The Late Latin root is defectivus, "to fail, revolt, or desert."
Vocabulary lists containing defective
Geography and World Regions
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Hello, Universe
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CTE Construction ("Core Curriculum: Introductory Craft Skills,") Vocabulary from Module One
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Misfolded and defective proteins accumulate inside cells, creating stress that can damage the pancreatic cells responsible for producing insulin.
From Science Daily ● Jul. 28, 2026
If your car is defective and you’re injured, you can sue the automaker.
From The Wall Street Journal ● Jun. 23, 2026
Huawei’s factories are estimated to produce usable chips only about 20% of the time, Goodrich said—meaning four out of every five come out defective.
From The Wall Street Journal ● Jun. 2, 2026
Judges at a district court in Hanover ruled in his favour, and said the family of four were entitled to a larger refund on their package holiday as it had been "defective".
From BBC ● May 6, 2026
Many more vignettes illustrating this and other simple logical errors might be cited, but the point is clear enough: both innumeracy and defective logic provide a fertile soil for the growth of pseudoscience.
From "Innumeracy: Mathematical Illiteracy and Its Consequences" by John Allen Paulos
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
