To M.A.P. Regarding 2 Thess 2:3
2 Thess 2:1-4 KJV "Now we beseech you, brethren, by the coming of our Lord Jesus Christ, and [by] our gathering together unto him, That ye be not soon shaken in mind, or be troubled, neither by spirit, nor by word, nor by letter as from us, as that the day of Christ is at hand. Let no man deceive you by any means: for [that day shall not come], except there come a falling away (g646 Apostasia) first, and that man of sin be revealed, the son of perdition; Who opposeth and exalteth himself above all that is called God, or that is worshipped; so that he as God sitteth in the temple of God, shewing himself that he is God.
The best translation of Apostasia is Apostasy. It's the root word where we get Apostasy from.