cruel的名词为cruelty，副词为cruelly
例句
1、
She was a monster. For one thing， she really enjoyed cruelty
她是个恶魔。一方面，她确实以残忍为乐。
2、
Cruelty is a normal attribute of human behaviour
残忍是人的天性之一。
3、
The deliberate cruelty of his words cut her like a knife.
他故意说的残酷无情的话对她像刀割一样。
