However, you could use some descriptive terms depending on the context:
* Assembly: This is a general term for a gathering of people.
* Convocation: This suggests a formal meeting, often with a specific purpose.
* Conference: This implies a gathering of people for discussion or debate.
* Session: This is often used for a series of meetings.
* Summit: This suggests a high-level meeting of important figures.
Ultimately, the best collective noun for "meeting" depends on the specific situation and what you want to emphasize.