( informal ) used to emphasize that you strongly believe what you are saying :
You haven't heard the last of this, believe you me!
( informal ) used to emphasize that you strongly believe what you are saying :
You haven't heard the last of this, believe you me!
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005