cack up

1. rude slang To cover or fill something with goop or gunk. In this usage, a noun or pronoun can be used between "cack" and "up." ("Cack" is a slang term for feces, used figuratively here.) You're going to cack up the engine if you don't get your oil changed more regularly.

2. rude slang By extension, to cause something to malfunction or work poorly. Usually used in passive constructions. I tried using a program to clean up and optimize my computer, but it's still cacked up.

3. rude slang To ruin, bungle, or make a mess of something. In this usage, a noun or pronoun can be used between "cack" and "up." The government really cacked up the new online system for filing tax returns. He didn't study for the test at all, so it's no surprise that he cacked it up.