An ASS MARANGUE is a sizeable amount of fecal matter pasted, squated, crapped out for whatever unsanitary reason all about the posterior effectively filling in the ass crack having the appearance of a large chocolate cake having been smashed against a person's butt.
When the doctor had Cess Pool Jimmy pull down his underwear for a rectal examination Jimmy's slowly peeled away his shorts exposing a huge ass marangue smeared all over Jimmy's rear end much to the doctor's surprize.
SHUT UP, STUPID! A (Pot Swan) is simply a hearty box car shit in the toilet having toilet paper as fluffy white swan like wings - DUMB ASS!
Any well cultured bowel movement that floats upon the surface of toilet bowl water substantial enough to pose as the body of a particular species of domesticated bowel swan having wings made out of toilet paper that gives the impression of that ready to fly out of the toilet look hence a mature appearing pot swan.