What does anathema mean?

An anathema is a curse or prohibition. You will find it used in the KJV of the Bible: "If any man love not the Lord Jesus Christ, let him be Anathema Maranatha" (1 Cor. 16:22). The NIV reads, "If anyone does not love the Lord a curse be on him. Come, O Lord!" Though the term may be translated differently it is used in several other texts, such as Deuteronomy 7:26; Acts 23:12; 23:14; 23:21; 1 Corinthians 12:3; Galatians 1:8-9; Romans 9:3. In the common Christian usage it is a formal condemnation of a person or group by the church, typically involving excommunication, and is generally reserved for those determined to be heretics.