Where does “undeedlii” come from?

undeedlii (Middle English) comes from Old English undēadlīc — immortal, for all eternity.

Ancestry of “undeedlii”, step by step

StepLanguageWordMeaning
1Old Englishundēadlīcimmortal, for all eternity
Every word from Old English undēadlīc
undeedlii — Etymology, Origin & Word History | Etymology Explorer