'Everlasting' in the Bible

And the angels which kept not their first estate, but left their own habitation, he hath reserved in everlasting chains under darkness unto the judgment of the great day.

just as Sodom and Gomorrah and the adjacent cities, since they in the same way as these angels indulged in gross immoral freedom and unnatural vice and sensual perversity. They are exhibited [in plain sight] as an example in undergoing the punishment of everlasting fire.