Learner's definition of REVELATION
1 [count] : a usually secret or surprising fact that is made known
The book includes many shocking/startling revelations about the mayor's personal life.
damaging personal revelations
The revelation that she was a drug user was not a surprise to me.
2 [count] : an act of making something known : an act of revealing something in usually a surprising way — often + of 3 [singular] : something that surprises you — often + to 4 : a sign or message from God