A mass meeting is an event where a large group of people gather together to discuss a particular issue or to hear a speaker. The term 'mass meeting' is often used in politics, when a large group of people come together to support a candidate or to discuss a particular issue. The term can also be used to describe any large gathering of people, such as a RALLY. A RALLY is an event where people come together to show their support for a cause or to express their opinion on an issue.