blind alley  死胡同;绝路；困境
 
【例句】

The thief ran into a blind alley and was cornered by the police.
小偷跑进了死胡同里，被警察逼得走投无路。
 
The team spent weeks working on a solution that turned out to be a blind alley, and they had to start over.
这个团队花了数周时间研究一个解决方案，结果证明是个死胡同，他们不得不重新开始。