blind alley
[noun]
Synonyms: dead end, cul-de-sac, impasse, pocket

[TahlilGaran] English Synonym Dictionary ▲

ˌblind ˈalley noun [countable]

1. a small narrow street with no way out at one end

2. a way of doing something that seems as if it will have a successful result, but which in fact does not:
False information has led the police up a series of blind alleys.

[TahlilGaran] Dictionary of Contemporary English ▲

blind alley
a method of thinking or acting which is not effective because it does not produce any results.
The latest evolutionary theory may turn out to be a blind alley.

[TahlilGaran] English Idioms Dictionary ▲

blind alley
n.
1. A narrow street that has only one entrance and no exit.
The blind alley ended in a brick wall.
2. A way of acting that leads to no good results.
John did not take the job because it was a blind alley.
Tom thought of a way to do the algebra problem, but he found it was a blind alley.

[TahlilGaran] English Idioms Dictionary ▲