To horseplay, joke around, behave immaturely or irresponsibly
To fool around.
To have sex with many partners.
To fritter aimlessly or distractedly, to procrastinate, to waste time.
To be playful; full of fun and high spirits; to not treat the situation seriously.
To do random unplanned work or spend time idly
To attempt to do something with a piece of equipment without understanding how it works.