Cross between a fart and a shit. Where you think your just going to be doing a ripper of a fart but it contains undesirable solid matter.
John: Man Im hungover, this greasy burger is great! Think I need to fart though.
John: Ah no that was a shart!
Paul: Man thats fucking disgusting!
John: Shit yeah, I better go do the wipe test
and change my undies!
Paul: Pwoarrr!! That stinks, fuck off!