An atrocity is a very bad and cruel thing that happens, especially a crime in a war.
The word atrocity makes people think of very bad things that make them feel sad, angry, or scared.
Examples:
The atrocity made everyone very sad.
The war was full of atrocities.
He was shocked by the atrocity.
The atrocity was so bad, it made the news.
The atrocity was the worst thing anyone had ever seen.
The atrocity was so bad, it made everyone cry.