Where does “twin” come from?

twin (Middle English) comes from Old English twīn, from Proto-West Germanic twiʀn, from Proto-Germanic twiznaz, from Proto-Indo-European dwisnós, from Proto-Indo-European dwóh₁ — two.

Ancestry of “twin”, step by step

StepLanguageWordMeaning
1Old Englishtwīndouble thread, twist, twine, linen-thread, linen
2Proto-West Germanictwiʀntwine, double thread
3Proto-Germanictwiznazthread, twine
4Proto-Indo-Europeandwisnósdouble
5Proto-Indo-Europeandwóh₁two

Words derived from “twin”

Every word from Proto-Indo-European dwóh₁ →Every word from Proto-Indo-European dwisnós →Every word from Proto-Germanic twiznaz →