noun
a secret piece of information that is known only by the people at a particular company :
The recipe for their drink is a closely guarded trade secret.
noun
a secret piece of information that is known only by the people at a particular company :
The recipe for their drink is a closely guarded trade secret.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005