1.to behave in a silly way, especially when you should be working or paying attention to something
2.to spend time doing things in a relaxed way
3.to waste time doing things that are not important
4.to try to change or repair something, especially when this is unnecessary or unsuccessful
5.to have sex or a sexual relationship with someone, especially when you should not
6.to treat someone badly, especially by changing your mind or by not doing what you promised
messes around