insider

/ษชnหˆsaษชdษš/

IPA: /IH0 N S AY1 D ER0/

noun
  1. 1

    A person who has special knowledge about the inner workings of a group, organization, or institution.

  2. 2

    A person who is within an enclosed space.

Source: https://en.wiktionary.org/wiki/insider