How you feel when you're hurdy gurdying so hard.
"Hey man, how's it going?"
"Oh, you know, just Hurdy Gurdying."
When you feel hella hurdy, to the point of gurdy.
"Ah freak man, you see that dude? He just got a visit from the hurdy gurdy man."
When you eat regular food and it makes you sick because you are temperamental. It can even make you bleed out the bum for no apparent reason. Regular people can eat the same thing and be fine.
I ate dinner last night, nothing out of the ordinary, and it gave me Gurdy Bum, I have no idea why, its so grosse and hurts. Why isn't anyone else sick today??