Trough
Old English trog, of Germanic origin; related to Dutch trog and German Trog, also to tree.
wiktionary
From Middle English trogh, from Old English troh, trog(“a trough, tub, basin, vessel for containing liquids or other materials”), from Proto-Germanic *trugą, *trugaz (compare West Frisian trôch, Dutch trog, German Trog, Swedish tråg), from Proto-Indo-European *dru-kó (compare Middle Irish drochta(“wooden basin”), Old Armenian տարգալ(targal, “ladle, spoon”), enlargement of *dóru(“tree”)). More at tree.
etymonline
trough (n.)
Old English trog "wooden vessel, tray, hollow vessel, canoe," from Proto-Germanic *trugaz (source also of Old Frisian, Old Saxon, Old Norse trog, Middle Dutch troch, Dutch trog, Old High German troc, German trog), from PIE *dru-ko-, from root *deru- "be firm, solid, steadfast," with specialized senses "wood, tree" and derivatives referring to objects made of wood. Originally pronounced in English with a hard -gh- (as in Scottish loch); pronunciation shifted to "-ff," but spelling remained.
