Learn the meaning, pronunciation, and usage of the word ' anti ' as a noun, adjective, and prefix. Find examples, synonyms, and related terms of ' anti ' in British and American English. Anti definition: A person who is opposed to something, such as a group, policy, proposal, or practice. ANTI definition: 1. opposed to or against a particular thing or person: 2. a person who is opposed to something or…. Learn more. When should you use ante vs. anti ? Examine their meanings and learn when to use ante or anti in a sentence.