mess up phrasal verb informal ( see also ↑ mess )
1 . mess something ↔ up to spoil or ruin something, especially something important or something that has been carefully planned:
It took me ages to get this right – I don’t want some idiot to mess it up.
She felt she’d messed up her whole life.
2 . mess something ↔ up to make something dirty or untidy:
Who messed up the kitchen?
3 . to make a mistake and do something badly:
I think I messed up on the last question.
mess something ↔ up
It doesn’t matter if you mess it up, you can always try again.
4 . mess somebody ↔ up to make someone have emotional or mental problems:
I messed up my kids.
5 . mess somebody ↔ up American English informal to hurt someone especially by hitting them