Some ‘Podunk’ Town In The Middle Of Nowhere – NPR
"We have no idea what the word means," says Ives Goddard, Senior Linguist Emeritus at the Smithsonian Institution, and a leading expert on Algonquian languages. "You'll be able to find guesses in the sources if you look around. Don't believe any of it."
(I did, in fact, find some definitions β the most plausible being from the Nimpuc Indian Association of Connecticut's Quarterly Newsletter: "Podunk or Pautunke, means 'where you sink in mire', a boggy place, in the Nipmuc dialect. But the Podunk called their homeplace Nowashe, 'between' rivers.")