abuse
It's cruel to abuse abuse victims.
The sentence highlights the irony of harming those who have already endured harm.

Meanings
to use wrongly or improperly; to mistreat
- Officials must not abuse their authority.
- Drivers who abuse speed limits face heavy fines.
the wrong or improper use of something; mistreatment
- Reports of abuse must be investigated promptly.
- Substance abuse affects millions of families.
Word origin
From Old French abuser ('to misuse'), from Latin abūsus, past participle of abūtī ('to use up, misuse'), formed from ab- ('away from, wrongly') + ūtī ('to use'). The verb-noun pronunciation distinction (/z/ vs /s/) is a regular feature of English known as voicing alternation, which also appears in 'use', 'house', 'advise/advice', and 'excuse'.
Fun fact
The /z/-to-/s/ shift between verb and noun is one of English's oldest fossil distinctions, going back to Old English where verbs retained voicing on suffixes that were later lost — leaving the modern voicing as the only surviving trace.