Where does “trough” come from?

trough (Middle English) comes from Old English trog, from Proto-Germanic trugaz, from Proto-Indo-European drukós.

Ancestry of “trough”, step by step

trough traces back through two separate lines of ancestry.

via Old English trog

StepLanguageWordMeaning
1Old Englishtrogtrough
2Proto-Germanictrugaztrough
3Proto-Indo-Europeandrukós—

via Old English troh

StepLanguageWordMeaning
1Old EnglishtrohAlternative form of trog
2Proto-Semiticṯin-two
Every word from Proto-Indo-European drukós →Every word from Proto-Germanic trugaz →Every word from Old English trog →