Insider

/ˈɪnˌsaɪ.dɚ/

Synonyms

  • informed person
  • insider trading
  • privileged member
  • whistleblower

Slang Meanings

A person who has inside information.
That guy is an insider; he knows everything about the industry!
Someone who belongs to a secretive or exclusive group.
She's an insider in the fashion world.