What is Bum Chunder?
1.
A projectile explosion from the arse of a lumpy nature.
I've just done a bum chunder in my pants!
See
2.
A drinking forfeit where person 1 bends over and pulls down their trousers. Person 2 lies underneath, and drinks a pint of lager which has been poured skillfully through person 1's bum crack. Person 2 has to drink the lager as it dribbles off the testicles of person 1.
Give him a bum chunder!
See