Apocalypse
The Greek word translated as The Revelation in Revelation 1:1 is apocalypse.
“The Revelation of Jesus Christ, which God gave unto him, to shew unto his servants things which must shortly come to pass; and he sent and signified it by his angel unto his servant John: . . . .”
The Greek word, apokalypsis, means:
1. laying bare, making naked
2. a disclosure of truth, instruction