From Longman Dictionary of Contemporary Englishchat roomˈchat room noun [countable] a place on the Internet where you can write messages to other people and receive messages back from them immediately, so that you can have a conversation while you are online
Examples from the Corpus
chat room• Or you might even run to a chat room.• Joining a chat channel, chat room on chat forum is like arriving at a party.• Now it's on every chat room and on all of the talk-radio shows.• If you are brand new, you can go to the beginning genealogy chat room.From Longman Business Dictionarychat roomˈchat room noun [countable] COMPUTING a place on the Internet where several people are able to send and read messages about particular subjectsA conversation about the case took place in the WBS-Talk political chat room last week. 