1.
If you ~ or mess about, you spend time doing things without any particular purpose or without achieving anything.
We were just messing around playing with paint...
Boys and girls will enjoy messing about with any kind of machine.
PHRASAL VERB: V P, V P with n
2.
If you say that someone is messing around with or messing about with something, you mean that they are interfering with it in a harmful way.
I’d like to know who’s been messing about with the pram.
PHRASAL VERB: V P with n
3.
If someone is messing around or messing about, they are behaving in a joking or silly way.
I thought she was messing about.
= fool around
PHRASAL VERB: V P
4.
If you mess someone around or mess them about, you treat them badly, for example by not being honest with them, or by continually changing plans which affect them. (mainly BRIT)
I think they’ve been messed around far too much.
PHRASAL VERB: V n P