An Etymological Dictionary of the German Language/Tändelei
Tändelei, f., ‘toying, trifling, dawdling,’ ModHG. only, is a derivative of Tand (in MidHG. once only tenterîe). In OHG. only a corresponding tantarôn, ‘to be mentally perplexed,’ is recorded. No further light can be thrown on the HG. stem tant.