muck something up

muck up

To ruin or mess something up. A noun or pronoun can be used between "muck" and "up." Boy, you really mucked up this report, and I don't have time to fix it right now.
See also: muck, up

muck something up

tv. to mess something up; to ruin something. Try not to muck it up this time.
See also: muck, something, up