A wrongful act, an offense, an injustice committed against someone
Adikēma (from adikeō, 'to wrong') denotes a specific act of wrongdoing — a misdeed, offense, or injustice. It appears three times in the NT: Acts 18:14 (Gallio dismissing charges against Paul — 'a crime or serious wrong'); Acts 24:20 (Paul challenging the Sanhedrin to identify any 'wrong' they found); and Revelation 18:5 ('her sins are piled up to heaven') where the related concept of accumulated offenses reaches divine judgment. The word stresses the concrete act rather than the general state of wickedness.
The two court appearances (Acts 18, 24) where adikēma appears show Paul consistently vindicated when facing secular legal systems — Roman courts found no wrongdoing in him. Luke likely includes this detail to demonstrate that the gospel is not socially destructive or criminal; it is Paul's accusers who are acting unjustly. This anticipates Paul's argument in Romans 13 that governing authorities are servants of God for good (Romans 13:4). Yet ultimately, all human injustice is exposed before the divine court (Revelation 18:5), where accumulated adikēmata meet perfect justice.