used to emphasize that sth should never happen or be allowed :
Under no circumstances should you lend Paul any money.
Don't open the door, in any circumstances.
used to emphasize that sth should never happen or be allowed :
Under no circumstances should you lend Paul any money.
Don't open the door, in any circumstances.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005