"Untruth" is a false, not true understanding, perversion of the Word of God's Will - the Scriptures of the Prophets, the Teachings of Jesus Christ and the Apostles.

"Untruth" is also various false teachings, false beliefs, false religious dogmas and political ideologies.  

"Untruth" is anything that is not in accordance with God's established Laws and Commandments, that is not in accordance with Truth, what God expresses and approves.

"Untruth" is everything that is not Truth, the opposite of Truth, Truth, a distorted, inaccurate, incorrect representation of reality.