From Longman Dictionary of Contemporary Englishmess up phrasal verb informal1 mess something ↔ upSPOIL 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 ↔ upUNTIDY 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 → mess→ See Verb table
Examples from the Corpus
mess up• Don't ask Terry to do it - she'll probably just mess it up.• I've practiced all week, but I'm still afraid I'll mess up.• We secretly organized a party for her, but then Bill messed everything up by telling her about it.• Who's messed up my nice clean kitchen?• The travel agents messed up the arrangements and there was no room for us at the hotel.• Don't mess up the living room - we have company coming tonight.• Danny messed up three plays and made us lose the game. 