An Etymological Dictionary of the German Language/Annotated/tüchtig

by Friedrich Kluge

tüchtig, adjective, ‘fit, able, qualified, excellent,’ from Middle High German (Middle German) tühtic (g), ‘serviceable, brave, sturdy’; allied to Middle High German (Middle German) tuht, feminine, ‘ability, fitness,’ an abstract of Modern High German taugen (compare also Tugend). Corresponding to Dutch deugdelijk, Anglo-Saxon dyhtig, English doughty.