1. "Herda-hada" or "Herda-hada-herda" can either refer to residents of the Southern American states, the Bible Belt, or any rural area in the United States, especially where "rednecks" can be found. This mostly Southern and Eastern Maryland, West Virginia and Kentucky to the Gulf Coast, and from the Atlantic coast to most of Texas and Oklahoma.
2. It can also refer to the Southern American English (SAE) speech dialect and the mockery thereof.