insider
Meaning 1:
A person who knows a lot about something because they are part of it. For example, if you are part of a secret club, you are an insider because you know all the secrets and special things about the club.
Other Words
A person who knows a lot about something because they are part of it. For example, if you are part of a secret club, you are an insider because you know all the secrets and special things about the club.