N-UNCOUNT
难以摆脱的困境；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渊了。
The research seemed founded on quicksand.
这项研究犹如建在流沙之上，基础极不稳固。