Midwestern people who use methamphetamines, women who like to seep around, obese people, country folks. Blanket insult for Midwesterners. Midwestern equivalent of redneck. Used in the show "It's Always Sunny in Philadelphia."
Adrian, that girl Megan is prairie trash, don't sleep with her.
Stop wearing camouflage jackets around in the city, that's such a prairie trash thing to do.