ˌwild ˈgoose ˌchase noun [countable]
a situation where you are looking for something that does not exist or that you are very unlikely to find, so that you waste a lot of time:
It looks like they’ve sent us on a wild goose chase.

[TahlilGaran] Dictionary of Contemporary English ▲

wild-goose chase
a situation where you waste time looking for something that you are not going to find, either because that thing does not exist or because you have been given wrong information about it.
After two hours spent wandering in the snow, I realised we were on a wild-goose chase.

When I found out that there was no Anita Hill at the university, I began to suspect that I had been sent on a wild-goose chase.

[TahlilGaran] English Idioms Dictionary ▲

wild goose chase
a chase that is futile or worthless; absurd or hopeless search
The motorcycle riders led the police on a wild goose chase.

The man led the police on a wild goose chase when he ran away from them downtown.

[TahlilGaran] English Idioms Dictionary ▲

wild goose chase
n. phr. An absurd and completely futile errand.
I was on a wild goose chase when I was sent to find a man who never really existed.

[TahlilGaran] English Idioms Dictionary ▲