given to or showing cruelty or violence
showing great ferocity
unpleasantly malignant or severe
said of an animal: dangerous or refractory
malicious; spiteful
vicious gossip
intensified by reciprocally interacting causes
a vicious wage-price spiral
having the nature or quality of vice; depraved
a man of vicious habits
said esp of language or reasoning: defective; faulty
viciously adv
viciousness noun
[Middle English via French from Latin vitiosus full of faults, corrupt, from vitium blemish, vice1]