Pronunciation: (in"sī'dur),[key] —n. 1. a person who is a member of a group, organization, society, etc.
2. a person belonging to a limited circle of persons who understand the actual facts in a situation or share private knowledge: Insiders knew that the president would veto the bill. 3. a person who has some special advantage or influence.
4. a person in possession of corporate information not generally available to the public, as a director, an accountant, or other officer or employee of a corporation.