Where does “sothfast” come from?

sothfast (Middle English) comes from Old English sōþfæst, from Old English sōþ, from Proto-West Germanic sanþ, from Proto-Germanic sanþaz, from Proto-Indo-European h₁sónts, from Proto-Indo-European h₁ēs- — to be.

Ancestry of “sothfast”, step by step

StepLanguageWordMeaning
1Old Englishsōþfæsttrue, trustworthy
2Old Englishsōþtrue, sooth; truth; true, actual, real
3Proto-West Germanicsanþtrue; truth
4Proto-Germanicsanþaztrue, real
5Proto-Indo-Europeanh₁sóntsactive participle of *h₁ésti; being, existence;...
6Proto-Indo-Europeanh₁ēs-to be

Words derived from “sothfast”

Every word from Proto-Indo-European h₁ēs- →Every word from Proto-Indo-European h₁sónts →Every word from Proto-Germanic sanþaz →