- trough
- O.E. trog, from P.Gmc. *trugoz (cf. O.Fris., O.S., O.N. trog, M.Du. troch, Du. trog, O.H.G. troc, Ger. trog), perhaps ultimately from PIE *drukos, from base *dru- "wood, tree" (see tree). Originally pronounced in Eng. with a hard -gh- (as in Scottish loch); pronunciation shifted to -f-, but spelling remained.