adjective used to describe something or some act which is lowclass, trashy, or gross. Something one does not wish to be associated with.

A backwards, backwoods, inbred, slow talking-slow thinking individual, usually white trash of some sort.
Bestiality is a sport and white lightening is a privilege. A po-dunk packs their toothless mouth with wads of chewing tobacco, masticating it with their cancer ridden gums.
This person can usually be observed at race car tracks, livestock auctions and moon pie factory's. They claim to be a religious preacher, all the while drinking hard liquor, gambling in secret locations and consorting with known prostitutes (more than likely another po dunk family member under the age of 16).
They believe that Dale Earnhardt was a hero/messiah, Hee-Haw is still the number one show on TV and sweet tea is the nectar of the gods ( be advised that to make their type of sweet tea, you seriously add more sugar than tea, which accounts for the high amount of toothless-ness).
Their culture is as rewarding as their language. The higher in the mountains that you go, the more guttural vernacular you will experience. At some points I have noticed that these po dunks can communicate by a combination of burps, farts, grunts and squeaks.

Low quality, low cost, un-cool thing or place.

This is actually a place. The ORIGINAL Podunk was an area in south-central Mass inhabited by the Podunk Indians. It is now known as East Brookfield, MA. It is listed in the oldest Webster's Dictionary as such, (plus, I'm from there!!) Common areas/landmarks in Podunk: Podunk Cemetary, High Rocks, Lake Lashaway, Devil's Kitchen, Hayden Lodge, Union Chapel. Also, the birthplace of Connie Mack!

Iowa Iowa Iowa Iowa Iowa Iowa

A small town where Meth is the primary industry, everyone knows it but no one seems to care.
Street racing thru main street is the Friday night entertainment.
Corn seems to be a reason for celebration, and fighting is an inhertated past-time.

Soup beans , corn bread and fried taters