Dutch word eeuwig comes from Dutch -ig, Dutch eeuw

Detailed word origin of eeuwig

Dictionary entry	Language	Definition
-ig	Dutch (nld)	-ed, having (when attached to a noun preceded by an adjective that describes the noun). -y; forms adjectives from nouns.
eeuw	Dutch (nld)	(by extension) a very long time, far too long, (an) eternity. Century, 100 years. Many years.
eeuwig	Dutch (nld)	Eternal Forever.

Words with the same origin as eeuwig