noun
atrocity
uh-TRAH-suh-tee/əˈtrɑːsəti/
An extremely cruel act or quality.
Beating a bound, defenseless prisoner is an atrocity.

Etymology
The pieces first describe the quality of being cruel or frightful. Atrocity shifted from enormous wickedness in general to a particular deed displaying that wickedness.
In context
Their mom is the one that's hurting them. Their mom is the one that's killing them. That's extreme atrocity and cruelty.
More examples
- Survivors gave evidence about the atrocities they had witnessed.
- No military goal could justify such an atrocity.
- The atrocity of the crime shocked even experienced investigators.
Forms
atrocity · atrocities
atrocious adjective — Extremely cruel, shocking, or appallingly bad.
Similar words
- outrage
- Can name any deeply offensive act, not necessarily extreme cruelty.
- brutality
- Emphasizes cruel violence as behavior or a quality.