- having a defect or flaw; faulty; imperfect: a defective machine.
- 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.
- a defective person or thing.
Origin of defective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- 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
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
Word Origin and History for undefective
mid-14c., from Middle French défectif (14c.) and directly from Late Latin defectivus, from defect-, past participle stem of deficere (see deficient). A euphemism for "mentally ill" from 1898 to c.1935. Related: Defectively; defectiveness.
Online Etymology Dictionary, © 2010 Douglas Harper
- Having an imperfection or malformation.
- Lacking or deficient in some physical or mental function.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.