VI'CIOUS, a. [L. vitiosus.]
1. Defective; imperfect; as a system of government vicious and unsound.2. Addicted to vice; corrupt in principles or conduct; depraved; wicked; habitually transgressing the moral law; as a vicious race of men; vicious parents; vicious children.3. Corrupt; contrary to moral principles or to rectitude; as vicious examples; vicious conduct.4. Corrupt, in a physical sense; foul; impure; insalubrious; as vicious air.5. Corrupt; not genuine or pure; as vicious language; vicious idioms.6. Unruly; refractory; not well tamed or broken; as a vicious horse.