to decide that you are no longer going to take part in sth that has been agreed :
He lost confidence and backed out of the deal at the last minute.
to decide that you are no longer going to take part in sth that has been agreed :
He lost confidence and backed out of the deal at the last minute.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005