a word used before a noun or noun phrase to indicate opposition to the concept expressed by the noun or noun phrase
You can refer to people who are opposed to a particular activity or idea as antis. Despite what the antis would tell you, hunting is for people from all walks of life
If someone is opposed to something you can say that they are anti it. That's why you're so anti other people smoking. = against for. nonsteroidal anti inflammatory drugs American Anti Slavery Society Anti Comintern Pact Anti Corn Law League Anti Federalists Anti Lebanon Mountains Anti Masonic Movement anti Semitism Malayan People's Anti Japanese Army