That friend of yours who always has a shit
girlfriend everyone has to put up with, or a crap best mate from school they always ask out with you, or
the person who finds the most
obnoxious person at a party and exposes everyone to them: i.e. someone who digs up prats.
"I thought she'd be fine at
the game, but all she did was talk about her holiday with
other girls during extra time. I feel
like such a pratdigger".