This is a Greek word untranslated in 1 Corinthians 16:22: it occurs also in Romans 9:3; 1 Corinthians 12:3; Galatians 1:8-9 and is uniformly translated “accursed.” The solemn passage in 1 Corinthians 16 is “If any man love not the Lord Jesus Christ, let him be accursed, Maranatha (the Lord cometh).” In Galatians it is said that if any person or even an angel from heaven preached any other gospel than that which they had received, let him be accursed. Two solemn denunciations relating to the person of the Lord Jesus and the gospel of God.
The word ἀνάθεμα was used for any votive offering in a heathen temple, which could not be redeemed; hence anything devoted. In the New Testament it is devoted to God’s curse, destruction.