A term that stupid people use accidentally when they really mean "self-deprecating" and clever people use on purpose to make poop jokes that stupid people wont get.
The big-time CEO used self-defecating humor to try and relax the crowd. He wanted them to see that he was just a regular guy. Unfortunately, he succeeded only in relaxing his own bowels. No amount of good press will clear that stink.
"I guess you should know that sudden brain injury causes the victim to simultaneously urinate, defecate, and bite down."
-Andy Dufresne to Bogs about refusing to suck his cock-a-doodle. From Rita Hayworth and Shawshank Redemption.