Run away from lovely Mickey Mouse (5)
I believe the answer is:
petty
'mickey mouse' is the definition.
(thesaurus)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for petty that I've seen before include "Small-time" , "Trifling" , "Trivial - small-minded" , "small" , "Insignificant or trivial" .)