Meaning of “revelation” - Learner’s Dictionary

revelation

noun uk us /ˌrevəlˈeɪʃən/

[ C ] a piece of information that is discovered although it was intended to be kept secret:

He resigned following revelations about his private life.
be a revelation

to be an extremely pleasant surprise:

Anna's boyfriend was a revelation.

(Definition of “revelation” from the Cambridge Learner’s Dictionary © Cambridge University Press)