A difficult task or someone who is difficult to persuade.
He's still not convinced although I tried my best to persuade him. Such a numb bum!
by sinthya April 30, 2006
This is what happens to a person's rear end after sitting for too long.
That movie was so long that I ended up with a major case of numb bum.
by Libertine September 04, 2009
The numbness in your anus after having anal sex for the first time.
I woke up with numb bum after last night's party... guess that means I'm gay.
by DerpSirsAlot October 12, 2015