forum is indeed Latin, but we use it in English (as when we say that the internet provides "a forum" for different views--to the extent that it still does, of course!).
In a Latin class, if you speak of "going to the Forum" or "buying something in the Forum," you know that the reference is to the center of town (of any town in the Roman world), where government offices and stores for selling things were located.
Forum is used in English (taken from Latin). This discussion area is referred to as a 'forum'. It has a few other usages: https://www.google.com/amp/s/dictionary.cambridge.org/amp/english/forum
What did you dictionary say?