 The "d" in Modern English "thunder" (from earlier Old English "þunor") is epenthetic, and is now found as well in Modern Dutch "donder" (cp Middle Dutch "donre", and Old Norse "þorr", Old Frisian "þuner", Old High German "donar" descended from Proto-Germanic *"þunraz").In Latin the term was "tonare" "to thunder".The name of the Nordic god Thor comes from the Old Norse word for thunder.