An Etymological Dictionary of the German Language/Annotated/treu

by Friedrich Kluge

treu, adjective, ‘true, faithful,’ from late Middle High German triuwe, for which classical Middle High German has getriuwe (hence Modern High German getreu), Old High German gitriuwi, ‘true, faithful, trusty, loyal.’ Properly a derivative of Old High German triuwa, Middle High German triuwe (Modern High German Treue), feminine; getreu, literally ‘possessing loyalty.’ in Old Saxon triuwi, Dutch trouw, Anglo-Saxon treówe, trŷwe (English true, truth, to trow, and to trust), Gothic triggws, ‘true.’ Teutonic treuwo- (treuwi-?), for pre-Teutonic dréwo-, is related to the assumed (see trauen) Aryan root drū̆, ‘to have confidence,’ with which Prussian druwis, ‘belief,’ is connected. Old High German triuwa, feminine, ‘fidelity,’ corresponds to Old Saxon treuwa, Anglo-Saxon treów, ‘fidelity,’ Gothic triggwa, ‘agreement, compact’; with the last signification, Italian tregua, French trève, ‘armistice,’ borrowed from Teutonic, are connected.