used to say that if sth is not successful, it is not because of a lack of effort :
If he doesn't manage to convince them, it won't be for want of trying (= he has tried hard) .
used to say that if sth is not successful, it is not because of a lack of effort :
If he doesn't manage to convince them, it won't be for want of trying (= he has tried hard) .
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005