Revelation, n.
Etymology: [F. révélation, L. revelatio. See Reveal.]
1. The act of revealing, disclosing, or discovering to others what was before unknown to them.
2. That which is revealed.
3. (Theol.) (a) The act of revealing divine truth. (b) That which is revealed by God to man; esp., the Bible. By revelation he made known unto me the mystery, as I wrote afore in few words. Eph. iii. 3.
4. Specifically, the last book of the sacred canon, containing the prophecies of St. John; the Apocalypse.
Shades of meaning
Revelation (L. re, back, and velum, veil), literally an unveiling, is the act or process of making known what was before secret or hidden, or what may still be future. Apocalypse (Gr. apo, from, and kalypto, cover), literally an uncovering, comes into English as the name of the closing book of the Bible. The Apocalypse unveils the future, as if to the very gaze of the seer; the whole gospel is a disclosure of the mercy of God; the character of Christ is a manifestation of the divine holiness and love; all Scripture is a revelation of the divine will. Or we might say that nature is a manifestation of the divine character and will, of which Scripture is the fuller and more express revelation.