forum

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The public square or marketplace of an ancient Roman city that was the assembly place for judicial activity and public business.
• noun A public meeting place for open discussion.
• noun A medium for open discussion or voicing of ideas, such as a newspaper, a radio or television program, or a website.
• noun A public meeting or presentation involving a discussion usually among experts and often including audience participation.
• noun An area of legal authority; a jurisdiction.
• noun A court of law or tribunal.

from The Century Dictionary.

• noun In Roman antiquity the market-place of a city.
• noun Hence A tribunal; a court; any assembly empowered to hear and decide causes

from the GNU version of the Collaborative International Dictionary of English.

• noun A market place or public place in Rome, where causes were judicially tried, and orations delivered to the people.
• noun A tribunal; a court; an assembly empowered to hear and decide causes.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A place for discussion.
• noun A gathering for the purpose of discussion.
• noun A form of discussion involving a panel of presenters and often participation by members of the audience.
• noun Internet An Internet message board where users can post messages regarding one or more topics of discussion.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a public facility to meet for open discussion
• noun a public meeting or assembly for open discussion