derk derk/dirk dirk/durk durk/derk-derk/dirk-dirk/durk-durk
A derogatory term synonymous with a hick/redneck; especially an Iowan. Coined from the sound fat construction workers of the area sound when laughing.
Two women sit, enjoying a meal, when two extremely obese construction workers walk into the restaurant (strangers to them), and exclaim, "Hey laydeys! DURK-DURK-DURK-HERK-DURK-DURK!" The women proceed to exchange a confused and disgusted look with one another.

There is no real way to spell this, as it is an onomatopoeia, hence the long title of "derk derk/dirk dirk/durk durk/derk-derk/dirk-dirk/durk-durk."