defective
Americanadjective
-
Sometimes defected having a defect or flaw; faulty; imperfect.
a defective machine.
- Synonyms:
- deficient, incomplete
-
Psychology. characterized by subnormal intelligence or behavior.
-
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
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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.
The flushing process has caused damage to the pipework, with more than 2,200 defective valves needing replaced.
From BBC ● Nov. 4, 2026
The implication was that Omar’s criticism of the country was itself evidence of a defective character.
From Salon ● Oct. 22, 2026
This is an odd analogy since the county isn’t arguing that oil is defective.
From The Wall Street Journal ● Oct. 6, 2026
The same cellular systems that preserve useful proteins also help eliminate defective ones, so changing that balance could have unintended consequences.
From Science Daily ● Oct. 3, 2026
This depended on their confidence in the reliability of measurements taken decades apart; others were quick to dismiss such findings as the result of defective technique.
From "The Invention of Science" by David Wootton
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Get a wordDefinitions 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.
