revelation

revelation · noun¹

1. Latin · derived fromrevēlātiō“disclosure”
2. Old French · derived fromrevelacion
3. Middle English · inherited fromrevelacioun
4. English todayrevelation

From Middle English revelacioun, from Old French revelacion, from Latin revēlātiō (“disclosure”), from revēlō (“to disclose”), re (“again”) + vēlō (“to cover”); by surface analysis, revelate + -ion.

Revelation · proper noun²

Proprialization from revelation. The translation decisions, from the original Greek to the conventional English choices Revelation and Apocalypse, are covered by Wikipedia at Book of Revelation § Title, authorship, and date.