( master keys)
A master key is a key which will open all the locks in a set, even though each lock has its own different key.
N-COUNT
( master keys)
A master key is a key which will open all the locks in a set, even though each lock has its own different key.
N-COUNT
Collins COBUILD Advanced Learner's English Dictionary. Английский словарь Коллинз COBUILD для изучающих язык на продвинутом уровне. 2006