An Etymological Dictionary of the German Language/Annotated/Tenne
Tenne, feminine, ‘threshing-floor,’ from the equivalent Middle High German tęnne, neuter, feminine, and masculine, Old High German tęnni, neuter. No corresponding word occurs in this sense in the allied Teutonic dialects. It has been connected with Anglo-Saxon dęnu, ‘valley,’ Anglo-Saxon and English den; but Tenne is rather a derivative of Tanne (literally ‘made of fir’).