to be involved in an illegal or dishonest activity:
He's the last person I'd expect to be mixed up in something like this.
I'd have to be crazy to get mixed up in that kind of thing.
to be involved with someone who has a bad influence on you:
When he left college he got mixed up with the wrong people.
3 [not before noun]
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 informalMP
confused and suffering from emotional problems [= screwed up]:
She's just a crazy mixed-up kid.