An Etymological Dictionary of the German Language/Trog
Trog, m., ‘trough,’ from the equiv. MidHG. and OHG. troc (g), m.; comp. Du. trog, AS. trog, E. trough, OIc. trog. The assumed Teut. trogo-, from which the cognate Ital. truogo, ‘trough,’ is borrowed, is based on pre-Teut. dru-kó-, which is rightly connected with the Aryan stem dru (dreu, deru), ‘tree, wood,’ discussed under Teer; comp. Sans. dru, dâru, ‘wood.’ Hence Trog is lit. ‘wooden article.’