be flogging a dead horse(redirected from been flogging a dead horse)
be flogging a dead horse
To be continuing to focus on an issue or topic that is no longer of any importance or relevance. I don't know why you're flogging a dead horse—the rest of us have moved on from that problem.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
be flogging a dead horseBRITISH or
be beating a dead horseAMERICAN
If someone is flogging a dead horse, they are wasting their time trying to achieve something that cannot be done. After putting in all that hard work it feels like we're flogging a dead horse — it's all very discouraging. You're beating a dead horse on this. These guys are defeated.
Collins COBUILD Idioms Dictionary, 3rd ed. © HarperCollins Publishers 2012