noun
1.
a place where gold is dug out of the ground
2.
a business or an activity that makes a large profit :
This restaurant is a potential gold mine.
noun
1.
a place where gold is dug out of the ground
2.
a business or an activity that makes a large profit :
This restaurant is a potential gold mine.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005