Define Pissing About Meaning

"James, stop pissing about! I'm trying to get a very important despatch out!"

"Don't have a go at me, Steve's not even at work today, at least I'm doing something!"

"Checking for drugs and porn in the lockers isn't helping!"

We were an hour late for dinner because the wife spent an hour pissing about with make up and doing her hair.
My pint was empty because my mate spent 20 minutes pissing about trying to chat up the barmaid.