See revelation in Webster's New World College Dictionary
noun
a revealing, or disclosing, of something
something disclosed; disclosure; esp., a striking disclosure, as of something not previously known or realized
Theol.
communication, by a divinity or by divine agency, of divine truth or knowledge; specif., God's manifestation of the divinity or of the divine will to humanity
an instance of this
that which is so communicated, disclosed, or manifested
something, as a writing or event, containing or showing such a communication, disclosure, or manifestation
the last book of the New Testament, ascribed to John (in full ); Apocalypse: abbrev. Rev or Rv