Insider

Part of speech: noun

Pronunciation: /ɪnˈsaɪdɚ/

Definitions

1. Someone who is a member of a particular group or organization and has privileged information or access not available to outsiders
2. An individual who belongs to an exclusive circle and possesses confidential knowledge or insight about internal matters
3. A person who is part of a community or system and holds special or secret information that outsiders do not have

Etymology: The word is simply "inside" plus the agent suffix "-er", and the suffix itself has a long pedigree. The "-er" ending descends from Old English "-ere", which in turn came from Proto-Germanic and, further back, from a Latin ending "-arius" that was used to mark a person connected with something. That Latin suffix passed into Old French as "-ier", and Middle English absorbed it, so the "-er" on "insider" is ultimately a Roman-era tool for naming people by their role. The base word "inside" is a much older English formation, with "in" and "side" joined into one word. Once "inside" was a noun meaning the interior of a thing, it was a short step to using it for people who sat within a circle of knowledge. "Insider" is therefore a transparent compound rather than a borrowing, and its meaning is built directly from the spatial sense of being on the inner side of something.

Synonyms: member, participant, associate, insider trader, confidant

Antonyms: outsider, stranger, newcomer, foreigner, alien