( BrE ) if people or things are thick / thin on the ground , there are a lot / not many of them in a place :
Customers are thin on the ground at this time of year.
( BrE ) if people or things are thick / thin on the ground , there are a lot / not many of them in a place :
Customers are thin on the ground at this time of year.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005