A colloquialism referring to a thick layer of unshakeable dust upon the soles of one's feet, jiffy feet is a term which owes its origins to the south eastern United States, specifically the more rural areas of North Florida and Southern Georgia. One does not attain the status of having jiffy feet until the dirt requires multiple and/or vigorous washings to remove in full.
Some people seem to enjoy their jiffy feet but most folks think jiffy feet are grody. If one has good arch definition, only certain areas of the foot will be covered in dirt.
Most people with jiffy feet are either homeless, hobos, or just extremely lazy. While the term jiffy feet is a Southernism, the phenomenon is not as some ascetics and certain breeds of hippies from all over creation may be found with jiffy feet. I knew a guy in New England who would have jiffy feet until the snow fell. His feet stank, as is common amongst jiffy feet.
Jiffy feet are largely considered to be a gross violation of health codes, especially in cities, where it is not uncommon to find old poop or vomit on the pavement.
This is why convenience stores have signage indicated "No Shirt No Shoes No Service". Which brings us to the origins of the term "jiffy feet" (courtesy of Lonnie Lonnington of the Jiffy Feet website) :
'This Term “Jiffy Feet” which is used to describe this phenomenon got its name because the predominate convenience store chain of the area was named the “Huntley Jiffy” or “Jiffy Store” for short and was owned and operated by the Orange Park based Huntley Family. Due to the 342 stores that peppered North Florida and Southern Georgia, The Term “Jiffy” became the generic phrase that all locals used to describe any and all convenience stores. And in the same manner, the term “Jiffy Feet” became the phrase that is used to describe any and all filthy feet, regardless of how they were acquired.
The general idea was: if one needed to go to a convenience store in a jiffy, and could not find adequate footwear, one went barefoot and hoped for the best. If the convenience store truly prized convenience, the store would allow the unshoed to make a purchase in a jiffy. Thus the name for the feet descended from the practicalities of commerce.
The exact location of where the term originated is not certain, but the epicenter is arguably in the Palatka / Orange Park / Middleburg Area. The Chain of Convenience stores was sold in 1990 by the Hunltey Family [sic]."'