1.
If you mix up two things or people, you confuse them, so that you think that one of them is the other one.
People often mix me up with other actors...
Depressed people may mix up their words...
Any time you told one of them something, they’d swear you’d mixed them up and told the other.
PHRASAL VERB : V n P with n , V P pl-n (not pron ), V pl-n P
2.
If you mix up a number of things, you put things of different kinds together or place things so that they are not in order.
I like to mix up designer clothes...
Part of the plan was that the town should not fall into office, industrial and residential zones, but mix the three up together...
This is music from a different era. I’ve taken those sounds from childhood and mixed them up with other things.
PHRASAL VERB : V P pl-n (not pron ), V pl-n P , V n P with n
3.
see also mixed up , mix-up