From Longman Dictionary of Contemporary Englishmixed upˌmixed ˈup adjective 1 → be/get mixed up in something2 → be/get mixed up with somebody3 [not before noun]CONFUSED confused, for example because you have too many different details to remember or think about I get all mixed up over the money whenever I travel abroad.4 (also mixed-up) informalMPCONFUSED confused and suffering from emotional problems SYN screwed up She’s just a crazy mixed-up kid. → mix up at mix1, mix-up
Examples from the Corpus
mixed up• There was so much paperwork that Brian got mixed up and forgot to sign the check.• a mixed up college kid 