tar·nal \ˈtärnəl, ˈtȧn-\adverb (or adjective) Etymology: alteration of eternal dialect: damned — used as a mild imprecation < paid a tarnal high price for it — C.G.Loomis > < fire is a cruel, tarnal thing — Conrad Richter > • tar·nal·ly\-əlē, -əli\adverb, dialect