make a muck of (something)

make a muck of (something)

To ruin, bungle, or spoil something. Primarily heard in UK. I really made a muck of that project at work—I'm going to get fired for sure! I'm afraid the accounting department made a complete muck of these numbers. We'll need to re-tally the entire ledger.
See also: make, muck, of

make a muck of

handle incompetently; bungle. British informal
See also: make, muck, of