Definition of defectives:
(adj) :
Having one or more defects.
(n) :
A person or thing considered to be defective.
(adj) :
(grammar, of a lexeme, especially a verb) Lacking some forms; e.g., having only one tense or being usable only in the third person.
(adj) :
(Arabic grammar, of a verb) Having a root whose final consonant is weak (ي, و, or ء).
(adj) :
(orthography, of a script) Not capable of representing all the phonemic distinctions of a language it is used to write.
(adj) :
(chiefly of abjad script) Spelled without matres lectionis, for example אמץ (ómets, “courage”) as opposed to the plene spelling אומץ where the letter vav ⟨ו⟩ indicates the vowel o.