A vicious argument.
A vicious horse.
A vicious rumor.
A vicious blow.
A vicious storm.
A forced, vicious style of prose.
An example of vicious is a wild animal who savagely attacks you.
An example of vicious is when you cruelly attack someone's looks and character for no reason.
A vicious blow to the stomach; vicious tactics in suppressing a rebellion.
A vicious dictator.
A vicious concoction.