What does insider mean?
An insider is someone who belongs to a particular group or has privileged knowledge of an organization, profession, event, or situation. The term can emphasize membership in a community, as in “industry insider,” or access to information unavailable to the general public, as in “insider information.” It is frequently used in business, media, government, and professional contexts, where knowledge of internal practices or decision-making is valuable. The adjective form, as in “insider knowledge” or “insider trading,” describes information, conduct, or perspectives associated with privileged access. While the word often implies special knowledge, it can also simply identify someone as a member of a group. Its contrast with “outsider” makes it useful whenever the distinction between belonging or having privileged access and being outside such a circle matters.
A member of a group, organization, profession, or community.
"The proposal was circulated among insiders before it was made public."
Often used in contexts such as “industry insider” or “local insider,” where membership or specialist knowledge is important.
A person who possesses privileged or confidential information about a business, institution, event, or other matter.
"An insider supplied investigators with confidential information."
This sense can suggest unauthorized disclosure or exploitation of privileged knowledge, depending on context.
Relating to people who have privileged access or knowledge, or to information obtained through such access.
"The company denied that the account was based on insider trading."
Common in business, financial, journalistic, and political contexts, especially in the expressions “insider information” and “insider trading.”
The plural is used for multiple people who belong to a group or possess privileged information.
"Industry insiders welcomed the announcement."
An insider is not simply someone who is physically within a group; the word often implies access to knowledge that outsiders do not have.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does insider come from?
The word “insider” was formed in the early 19th century from “inside” and the suffix “-er,” with “-er” indicating a person or thing associated with a particular activity, group, or position. The underlying element “inside” had already been established in English for both the interior of something and, figuratively, an inner or privileged group. The modern sense involving a member of a group developed through this broader figurative use of “inside.”
How insider is actually used
The noun is neutral when referring to membership in a group but often suggests special or confidential knowledge when used by itself. The adjective is common in business, media, and political contexts. In some uses, especially when contrasted with outsiders, “insider” can carry a critical or dismissive connotation.