insider

/ɪnˈsaɪdɚ/

Proposed by a contributor, not yet supported by evidence.

Also seen as: insiders

Sense 1

Meaning · English

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

Noun

Examples

Near-synonyms: initiate, old hand, habitué

Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01)

Sources & notes

Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01 via kaikki.org).

Sense 2

Meaning · English

A person who is within an enclosed space.

Noun

Examples

To the insider, the ceiling is like a small firmament twinkling with astral radiations.

Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01)

Sources & notes

Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01 via kaikki.org).

Common questions

What does “insider” mean?

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

Is “insider” formal or informal?

No register label has been reviewed yet — treat it as neutral and check the usage notes above.