( old-fashioned ) used in questions to show that you are annoyed or surprised :
What the devil do you think you're doing?
( old-fashioned ) used in questions to show that you are annoyed or surprised :
What the devil do you think you're doing?
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005