General wickedness:
* malus: This is the most general and common term for "evil" or "wicked".
* nefastus: This word implies something that is "unlucky" or "ominous", and can also be used to describe something wicked.
* improbus: This word implies something that is "unjust", "unprincipled" or "wicked" in a moral sense.
Specific types of wickedness:
* ferox: This refers to something "savage", "fierce", or "cruel".
* crudelis: This means "cruel" or "heartless".
* atrox: This means "atrocious", "horrible", or "wicked" in a very extreme sense.
Other considerations:
* maleficus: This refers to someone who practices "evil magic" or "sorcery."
* perversus: This means "perverted" or "wicked" in a moral sense, often implying a deviation from what is considered good or right.
The best choice for you will depend on the specific context and the specific shade of "wickedness" you are trying to convey.