To fart whilst performing a cartwheel. Hilarity ensues.
Robert: Oh man! You should've seen it, Tricia hyped up this trick then ended up doing a fartwheel!
Matt: Lulz.
(V) The act of flatulating while ass up in a cartwheel position and completing the cartwheel in an upright position centered directly in the middle of ones own ass cloud
Did you see that gymnast's face after she did a fartwheel