N-UNCOUNT
難以擺脫的困境；不可靠的局面
You can refer to a situation as quicksand when you want to suggest that it is dangerous or difficult to escape from, or does not provide a strong basis for what you are doing.
例句
I was about to sink into the quicksand of sin...
我就要陷入罪孽的深淵了。
The research seemed founded on quicksand.
這項研究猶如建在流沙之上，基礎極不穩固。