past master

柯林斯词典

1. N-COUNT If you are a past master at something, you are very skilful at it because you have had a lot of experience doing it. 行家; 老手[usu N 'at/in/of' n]
He was a past master at manipulating the media for his own ends. 操縱媒躰爲自己服務他是老手。
She is an adept rock-climber and a past master of the obstacle course. 她擅長攀巖，也是障礙超越訓練場上的老手。