How can I provide a short definition of the following meeting terminology: meeting requirements, agenda, purpose, format, and participants?

I will give a brief description that you can elaborate on when using them in further academic work.
Meeting requirements: the meeting requirements are the necessary items or events that are supposed to take place, as well as any other requirements that may be included, such as duration, record keeping policies, and rules of conduct.
Agenda: the agenda is the list or summary of items that will be discussed in a meeting. This is also used for record keeping.
Purpose: a meeting's purpose is fairly straightforward to determine. The purpose is the reason behind calling the meeting (informational session, weekly update, disciplinary, etc.).
Format: a meeting's format is the way in which it is structured. Will it be a virtual meeting? Will it be a simple presentation with one speaker? Will it be an open forum?
Participants: a meeting's participants are simply the people who attend the meeting, typically written as a list and noted at the beginning of the agenda.