Where does “unwindeth” come from?

unwindeth (English) comes from English unwind, from Middle English unwinden, from Old English unwindan, from Proto-Germanic andawindaną — to unwind.

Ancestry of “unwindeth”, step by step

unwindeth traces back through two separate lines of ancestry.

via English unwind

StepLanguageWordMeaning
1EnglishunwindTo separate; To disentangle; To relax; to chill...
2Middle Englishunwinden—
3Old Englishunwindanto unwind, unwrap what is wrapped up
4Proto-Germanicandawindanąto unwind

via English eth

StepLanguageWordMeaning
1EnglishethA letter introduced into Old English to...
Every word from Proto-Germanic andawindaną →Every word from Old English unwindan →Every word from Middle English unwinden →