Meaning of DEFICIENT in English

DEFICIENT

/ dɪˈfɪʃnt; NAmE / adjective

1.

deficient (in sth) not having enough of sth, especially sth that is essential :

a diet that is deficient in vitamin A

2.

( formal ) not good enough :

Deaf people are sometimes treated as being mentally deficient.

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WORD ORIGIN

late 16th cent. (originally in the theological phrase deficient cause , denoting a failure or deficiency that has a particular consequence): from Latin deficient- failing, from the verb deficere desert or fail, from de- (expressing reversal) + facere do.

Oxford Advanced Learner's English Dictionary.      Оксфордский английский словарь для изучающик язык на продвинутом уровне.