vicious
A thing or a person that is vicious is very mean or extremely cruel and dangerous.
- The man was a victim of a vicious attack.
- A vicious storm killed dozens of people.
- Melinda felt humiliated by a vicious rumor about her and another coworker.
- Two boys got into a vicious fight on the playground.
- The vicious battle in northern Syria lasted several days.
- Living in poverty creates a vicious cycle* that’s hard to break, but there’s hope through education.
The adverb form for this word is “viciously.”
- During the debate, the candidates viciously attacked each other’s reputation in a verbal exchange.
- Slaves who worked on American plantations were beaten viciously or killed if they ever tried to escape.

His dog was the victim of a vicious attack by a wolf.
*vicious cycle: a bad situation that constantly repeats itself and is hard to escape.