1. an extremely wicked or cruel act, typically one involving physical violence or injury
2. the quality of being shockingly cruel and inhumane

Examples

• The war crimes tribunal investigated numerous atrocities committed during the conflict.
• Witnesses testified about the atrocities they had seen in the prison camp.
• The documentary exposed the atrocity of the regime’s treatment of political prisoners.
• History books record the atrocities of the Holocaust.
• The soldiers were shocked by the atrocity of the massacre.
• International law seeks to prevent such atrocities from happening again.
• The atrocity of the bombing left the entire nation in mourning.