The word 'vicious' originates from the Latin vitiosus, meaning 'full of faults' or 'defective', which itself derives from vitium, meaning 'fault' or 'vice'. This root concept of a moral flaw or imperfection passed through Anglo-French and Middle English, where it initially described a flawed or immoral character. Over time, the semantic focus sharpened from general faultiness to specifically denote a disposition characterized by cruelty, malice, or savage aggression, linking the ancient idea of a moral defect to the modern sense of deliberate wickedness or violence.

Structure: vic (fault, defect) + ious (adjective-forming suffix) vic (from Latin vitium, meaning fault, defect, vice); ious (from Latin -iosus, an adjective-forming suffix meaning full of or characterized by)