Where does “fainteth” come from?

fainteth (English) comes from English faint, from Middle English fainten.

fainteth (English): third-person singular simple present indicative...

Definitions

  1. third-person singular simple present indicative...

Ancestry of “fainteth”, step by step

fainteth traces back through two separate lines of ancestry.

via English faint

StepLanguageWordMeaning
1EnglishfaintLacking strength; weak; languid; inclined to lose...
2Middle Englishfainten

via English eth

StepLanguageWordMeaning
1EnglishethA letter introduced into Old English to...
Every word from Middle English fainten
fainteth — Etymology, Origin & Word History | Etymology Explorer