Noun

A dead end is a street, pathway, or route that has no exit or outlet at one end, meaning that it is a dead end or cul-de-sac. It can also refer to a situation or project that has no further potential for progress or success, and is therefore without any further possibilities of advancement or growth. In either case, a dead end represents a point of cessation or blockage where further movement or progress is impossible or extremely difficult to achieve.

Example

1. After driving for miles, I realized the road I was on was a dead end, with no way to turn around or go forward.
2. Despite his best efforts, John's business venture had reached a dead end, with no more potential for growth or profitability.
3. The detective followed the clues and eventually found himself at a dead end, unable to solve the case without further evidence.