IT WON'T DO


Meaning of IT WON'T DO in English

( especially BrE ) used to say that a situation is not acceptable and should be changed or improved :

This is the third time you've been late this week; it simply won't do.

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