an extremely dirty whore who's cunt looks like an old arby's roast beef and cheddar sandwiched in a catchers mit.
Man my cousin told me dat bitch is a "dirty ferg"
by george sandbar February 17, 2004
Reaming a dude from behind (doggy-style) and then rimming his asshole with your finger with which you run it (fecal matter and all) under his nose as to make a moustache with. Similar to the Dirty Sanchez, except strictly male related.
My boyfriend Leonard was pissed, so I gave him a Dirty Ferg last night.
by DirtyFerg June 26, 2010