An Etymological Dictionary of the German Language/tüchtig

by Friedrich Kluge

tüchtig, adj., ‘fit, able, qualified, excellent,’ from MidHG. (MidG.) tühtic (g), ‘serviceable, brave, sturdy’; allied to MidHG. (MidG.) tuht, f., ‘ability, fitness,’ an abstract of ModHG. taugen (comp. also Tugend). Corresponding to Du. deugdelijk, AS. dyhtig, E. doughty.