1. upset, worried, and confused, especially because of personal problemsHe's just a mixed-up kid.
2. temporarily confused
I just got mixed up and thought she wanted us to come early.
3. involved, esp. with someone or something bad or dangerous
He was a great athlete at school, but he got mixed up with the wrong crowd and stopped training.
4. (of names, information, files, etc.) put into the wrong place or order, esp. when put where similar things belong. = disordered
They got his records mixed-up (= confused information about him with someone else's information)