Bedeutung von “muck sth up” — Learner’s Dictionary

muck sth up

informal phrasal verb with muck us uk /mʌk/ verb

to do something badly, or to spoil something:

I mucked up the interview.
She lost her car keys and that mucked up the whole weekend.

(Definition von “muck sth up” aus dem Cambridge Learner's Dictionary © Cambridge University Press)