From Old Danish trodhe, trædhe, from Old Norse troða, from Proto-Germanic *trudaną (“to tread”), cognate with Norwegian Bokmål tre, Swedish träda, English tread, German treten. The modern Scandinavian form with e-vocalism is influenced by Middle Low German treden. The o-vocalism is retained in Norwegian Nynorsk trå and Danish tråde. Possibly, the verb may also have absorbed the related verb Old Norse treðja (“to tread down”), from Proto-Germanic *tradjaną.