1) Abnormal 2) Bad 3) Deficient 4) Faulty 5) Flawed 6) Impaired 7) Imperfect 8) Infelicitous 9) Malfunctioning 10) Marred 11) Unsound 12) Untrustworthy 1) Faulty 2) French word used in English 3) Having a defect 4) Having a defect or flaw 5) Imperfect 6) Not working properly 7) Subject to a recall 8) When something is not working 
• (a.) Lacking some of the usual forms of declension or conjugation; as, a defective noun or verb. • (a.) Wanting in something; incomplete; lacking a part; deficient; imperfect; faulty; -- applied either to natural or moral qualities; as, a defective limb; defective timber; a defective copy or account; a defective character; defective rul...
Denoting or exhibiting a defect; imperfect; a failure of quality. ... (05 Mar 2000) ... 
adj. Having an imperfection that is so great that it cannot fulfill its function.
De·fect'ive adjective [ Latin defectivus : confer French défectif . See Defect .] 1. Wanting in something; incomplete; lacking a part; deficient; imperfect; faulty; -- applied either to natural or moral qualities; as, a defective limb; defective timber; a 
Type: Term Pronunciation: dĕ-fek′tiv Definitions: 1. Denoting or exhibiting a defect; imperfect; a failure of quality.
Incapable of fulfilling its function, due to an error or flaw.
[adj] - having a defect 2. [adj] - markedly subnormal in structure or function or intelligence or behavior
faulty adjective having a defect; `I returned the appliance because it was defective`
having a defect or flaw; faulty; imperfect: a defective machine. · characterized by subnormal intelligence or behavior. · (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.
having a flaw