Define chat room: a Web site or computer program that allows people to send messages to each other instantly over the Internet. The term chat room, or chatroom, is primarily used to describe any form of synchronous . Look up chat room in Wiktionary, the free dictionary. Chat room definition, a branch of a computer network or a software application in which participants can engage in real-time discussions about a specific topic. an area on the Internet or other computer network where u Meaning, pronunciation, example sentences, and more from Oxford Dictionaries. Chat Room. A chat room is a virtual place on the Internet where people can get together and talk. They use programs which allow real time chat to take place. Commonly used wherever people get online -- including IMing, SMSing, cell phones, Blackberries, PDAs, Web sites, games, newsgroup postings, in chat rooms, Search NetLingo! · Top 50 Most Popular Text Terms · Acronyms · Smileys.