make a hash of something
make a hash of (something)
To ruin, bungle, or spoil something. I really made a hash of that project at work—I'm going to get fired for sure! I'm afraid the accounting department made a complete hash of these numbers. We'll need to re-tally the entire ledger.
make a hash of somethingINFORMAL
If you make a hash of a job or task, you do it very badly. The Government made a total hash of things and wasted a small fortune. She fumbled with the trolley and made a hash of stacking the food trays.