WordNet (r) 3.0 (2006):

chat room
    n 1: a site on the internet where a number of users can
         communicate in real time (typically one dedicated to a
         particular topic) [syn: chat room, chatroom]

The Free On-line Dictionary of Computing (30 December 2018):

channel
chat room
room

    (Or "chat room", "room", depending on the system in
   question) The basic unit of group discussion in chat systems
   like IRC.  Once one joins a channel, everything one types is
   read by others on that channel.  Channels can either be named
   with numbers or with strings that begin with a "#" sign and
   can have topic descriptions (which are generally irrelevant to
   the actual subject of discussion).

   Some notable channels are "#initgame", "#hottub" and
   "#report".  At times of international crisis, "#report" has
   hundreds of members, some of whom take turns listening to
   various news services and typing in summaries of the news, or
   in some cases, giving first-hand accounts of the action
   (e.g. Scud missile attacks in Tel Aviv during the Gulf War in
   1991).

   [Jargon File]

   (1998-01-25)