look up any word, like bae:
 
1.
to have anal sex
Hey bigboy how about a bumjack?
by bruce February 08, 2004
 
2.
the exercise of anal sex with one partners arsehole masturbating the others penis.
After we sucked each other off i gave the stud a bum jack he would never forget
by p.m.n August 12, 2003
 
3.
The act of stealing something through burglary or mugging. Perpetrated by a homeless person.
Sam: Dude my backpack is gone; I left it in the park and now it's not there.

Matt: I bet you got bum jacked, there are hundreds of 'em in that park.

or

Matt: Jesus christ!!

Sam: What?

Matt:I just lost my wallet to a bum!

Sam: Dude you just got bum jacked!!
by mvellone September 08, 2008