Endless etymology in English

English word endless comes from Proto-Germanic *andijaz (End.), Proto-Germanic - lausaz

Dictionary entry	Language	Definition
*andijaz	Proto-Germanic (gem-pro)	End.
- lausaz	Proto-Germanic (gem-pro)
ende	Old English (ang)	End, limit, border, corner.
*andijalausaz	Proto-Germanic (gem-pro)	Endless.
endeleas	Old English (ang)	Endless, infinte; unending; unendly, eternal; everlasting.
endelēas	Old English (ang)
endeles	Middle English (enm)
endless	English (en)	(obsolete) Without profitable end; fruitless; unsatisfying.. Extending indefinitely.. Having no end.

Endless etymology