The smell that emanates from the sack and or grundle area of anyone, particularly hobo's. Turds would be like roses compared to this pungent dry sweaty sack smell. The stench is so strong that you dryheave standing over the toilet. Hobo Sack stains porcelain with its tremendous odor.
Imagine a hobo riding the rail across the country, running from train to train to catch connections, sleeping in steamy hot, box-cars taking part in all types of un-savory hobo orgies all whilst not showering or considering washing the sack area...for months.
You may walk into a public bathroom and get hit with the smell. Not turdy, straight sack smell, Hobo Sack smell.