a thing or situation which seems to have no limits or seems never to end :
There isn't a bottomless pit of money for public spending.
the bottomless pit of his sorrow
a thing or situation which seems to have no limits or seems never to end :
There isn't a bottomless pit of money for public spending.
the bottomless pit of his sorrow
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005