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