noun
[ usually sing. ] an important principle that should be followed when doing sth in order to be successful :
The golden rule in tennis is to keep your eye on the ball.
noun
[ usually sing. ] an important principle that should be followed when doing sth in order to be successful :
The golden rule in tennis is to keep your eye on the ball.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005