The word "insider" has various synonyms that describe a person who possesses unique knowledge or access to something. Some of the common synonyms for an insider include specialist, expert, sworn confidant, authority, privileged knowledge holder, and insider trader. Many times, an insider is used to describe someone who has inside information on a particular topic and possesses exclusive knowledge that no one else has access to. Other synonyms for insider include insider observer, insider dealer, insider witness, insider confidant, and insider analyst. Regardless of the term used, an insider is someone who has a significant advantage over others with respect to the information they hold.