Example:

1. The war was full of atrocities.

2. He committed atrocious acts against his fellow prisoners.

3. She's been accused of atrocity against her employees.

4. I'm not sure if I can trust her because she's always been so atrocious.

Synonyms: abomination, outrage, heinousness, monstrosity, savagery

Antonyms:  benevolence, mercy, goodwill, kindness, virtue