Dictionary.com
Thesaurus.com
Synonyms

defective

American  
[dih-fek-tiv] / dɪˈfɛk tɪv /

adjective

  1. Sometimes defected having a defect or flaw; faulty; imperfect.

    a defective machine.

    Synonyms:
    deficient, incomplete
    Antonyms:
    complete, perfect
  2. Psychology. characterized by subnormal intelligence or behavior.

  3. 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

  1. a defective person or thing.

defective British  
/ dɪˈfɛktɪv /

adjective

  1. having a defect or flaw; imperfect; faulty

  2. (of a person) below the usual standard or level, esp in intelligence

  3. grammar (of a word) lacking the full range of inflections characteristic of its form class, as for example must, which has no past tense

"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

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."

Keep Reading on Vocabulary.com

Vocabulary lists containing defective

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.

Defective cores can be disabled, leaving a chip that still functions perfectly well to power different, often cheaper devices—in this case an entry-level laptop instead of a top-of-the-line iPhone.

From The Wall Street Journal • May 18, 2026

Defective compaction prevents the formation of the structure that ensures the embryo can implant in the uterus.

From Science Daily • May 1, 2024

Defective mitochondria fail to fuel the body and lead to brain damage, muscle wasting, heart failure and blindness.

From BBC • May 9, 2023

Two said they and others had submitted letters of complaint at SAMR's Defective Product Administrative Center after contact with BYD proved fruitless.

From Reuters • Jun. 30, 2022

Labeled Downloadable Cognizance: Defective, rows of Cogs sit lined in tiny holders like rings in a jewelry store.

From "The Last Cuentista" by Donna Barba Higuera

Vocabulary.com logo
by dictionary.com

Look it up. Learn it forever.

Remember "defective" for good with VocabTrainer. Expand your vocabulary effortlessly with personalized learning tools that adapt to your goals.

Take me to Vocabulary.com