A Southernism that means "Excuse me?" or simply "What did you say?" Usually said in a tone of utter cluelessness. Great example in a Space Ghost ep, when he's shooting the weird pod thingie with his laser and it keeps feeding on the laser and he's told "So stop shootin' it!" and he says the above, quite blankly and...I guess you had to be there. It was funny, honest.