This long word is made up from two Latin words that we find in the Latin version of the last book of the Holy Bible, in Revelation 20:2-7, namely, mille anni, meaning “a thousand years.”
... 2. What does Revelation 20:4-6 say about the millennium?
2 In proceeding to get the answer to this important question, let us read the prophetic verses about Christ’s reign, in Revelation 20:4-6: “And I saw seats: and they sat upon them: and judgment was given unto them: and the souls of them that were beheaded for the testimony of Jesus and for the word of God, and who had not adored the beast nor his image, nor received his character on their foreheads or in their hands; and they lived and reigned with Christ a thousand years.