1 definition by Rok Mriscan

The act of taking a shit on a woman's chest, then pushing one's face in between the shit covered ample breasts, and rocking one's head side to side while making a rapid lip moving motorboat engine sound.

Similar to a motorboat with the addition of the feces.
Did you motorboat that girl with the big tits?
No man, I had the runs so I did a mudderboat instead!
by Rok Mriscan August 22, 2007
Get the mudderboat mug.