Noun

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

   Trish was an admin member on three forums, and had no trouble at all when it came to moderating them.

Usage notes

• Ref: Modern English Usage, 2nd Edition, ed. Sir Ernest Gowers, Oxford 1968 (article '-um', p.658).