— used after a negative statement to say that something is even less likely or possible than the thing previously mentioned更别提,更不用说(用在否定句后,表示此事的可能性比前者更小)
I don't eat eggs, much less meat.我不吃鸡蛋,更别提肉了。
He can't run a mile, much less complete a marathon.他连一英里都跑不到,更不用说跑一场马拉松了。
: not to mention—used especially in negative contexts to add to one item another denoting something less likely
He had trouble paying for a car, much less a high-definition TV.And so it appears that he is never going to get out of the eighth grade, much less ever make it to college. Thomas Meehan