mess around ( also mess about British English ) phrasal verb informal ( see also ↑ mess )
1 . to spend time lazily, doing things slowly and in a way that is not planned:
He spent his vacation messing around on the farm.
2 . to behave in a silly way when you should be paying attention or doing something sensible SYN fool around :
Stop messing around and get ready for school.
3 . mess somebody around to cause a lot of problems for someone, especially by changing your mind often and not being completely honest:
Don’t mess me around – I want the money you promised me.