troughyoudaoicibaDictYouDict[trough 词源字典]
trough: [OE] Etymologically, a trough is something made out of ‘wood’. Its ultimate source is Indo-European *drukós, a derivative of the base *dru- ‘wood, tree’ (source also of English tree). This passed into prehistoric Germanic as *trugaz, which has since diversified into German and Dutch trog, Swedish tråg, Danish trug, and English trough. English trug ‘shallow basket’ [16] is a variant of trough.
=> tray, tree, trug[trough etymology, trough origin, 英语词源]
trough (n.)youdaoicibaDictYouDict
Old English trog "wooden vessel, tray, hollow vessel, canoe," from Proto-Germanic *trugaz (cognates: Old Frisian, Old Saxon, Old Norse trog, Middle Dutch troch, Dutch trog, Old High German troc, German trog), from PIE *dru-ko-, from root *dru-, *deru- "wood, tree" (see tree (n.)). Originally pronounced in English with a hard -gh- (as in Scottish loch); pronunciation shifted to "-ff," but spelling remained.