Vicious means mean-spirited, cruel, or evil. It can also describe something that is faulty, defective, or unsound. Find out more about the word's origin, usage, and translations. Vicious definition: spiteful; malicious .. See examples of VICIOUS used in a sentence. Explore the meaning of the term ' vicious ,' its etymology, contexts in which it's used, and how it influences language today. Understand related terms, synonyms, antonyms, and notable quotations. vicious meaning , definition , what is vicious : violent and cruel in a way that hurts so...: Learn more.