defective

/D IH0 F EH1 K T IH0 V/
noun
  1. 1

    A person or thing considered to be defective.

adjective
  1. 1

    Having one or more defects.

  2. 2

    (grammar, of a lexeme, especially a verb) Lacking some forms; e.g., having only one tense or being usable only in the third person.

  3. 3

    (Arabic grammar, of a verb) Having a root whose final consonant is weak (ูŠ, ูˆ, or ุก).

Synonyms

Source: https://en.wiktionary.org/wiki/defective