( informal ) used to tell sb that it is not worth wasting time and effort saying sth because it will not change anything :
Save your breath—you'll never persuade her.
( informal ) used to tell sb that it is not worth wasting time and effort saying sth because it will not change anything :
Save your breath—you'll never persuade her.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005