Mix up, confuse (6)
I believe the answer is:
muddle
I believe this is a double definition.
'mix up' is the first definition.
(I know that muddle is a kind of mix up)
'confuse' is the second definition.
(I know that muddle is a kind of confuse)
(Other definitions for muddle that I've seen before include "disorganisation" , "Confuse" , "Disorder, jumble" , "State of confusion and disorder" , "disorderly state of affairs" .)