noun
1.
a road, passage, etc. that is closed at one end :
The first street we tried turned out to be a dead end.
2.
a point at which you can make no further progress in what you are doing :
We had come to a dead end in our research.
He's in a dead-end job in the local factory (= one with low wages and no hope of promotion) .
These negotiations are a dead-end street (= they have reached a point where no further progress is possible) .