noun
past master (at sth / at doing sth) a person who is very good at sth because they have a lot of experience in it
SYN expert :
She's a past master at getting what she wants.
noun
past master (at sth / at doing sth) a person who is very good at sth because they have a lot of experience in it
SYN expert :
She's a past master at getting what she wants.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005