WordReference Random House Learner's Dictionary of American English © 2026
de•fec•tive /dɪˈfɛktɪv/USA pronunciation
adj.
WordReference Random House Unabridged Dictionary of American English © 2026- faulty;
imperfect;
not working properly or effectively:One of the tires was defective.
de•fec•tive
(di fek′tiv),USA pronunciation adj.
n.
de•fec′tive•ly, adv.
de•fec′tive•ness, n.
- having a defect or flaw;
faulty;
imperfect:a defective machine. - Psychologycharacterized 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.
n.
- a defective person or thing.
- Late Latin, as above
- Middle French
- Late Latin dēfectīvus, equivalent. to dēfectus (see defect) + -īvus -ive; replacing Middle English defectif
- 1375–1425
de•fec′tive•ness, n.
- 1.See corresponding entry in Unabridged incomplete, deficient.
- 1.See corresponding entry in Unabridged perfect, complete.
'defectively' also found in these entries (note: many are not synonyms or translations):