I. di-ˈfek-tiv adjective
Date: 14th century
1.
a. : imperfect in form or function : faulty
a defective pane of glass
b. : falling below the norm in structure or in mental or physical function
defective eyesight
2. : lacking one or more of the usual forms of grammatical inflection
must is a defective verb
• de·fec·tive·ly adverb
• de·fec·tive·ness noun
II. noun
Date: 1592
: a person who is subnormal physically or mentally