C1noun2K

Insider

UK /["/ɪnˈsaɪdə(r)/"]/US /["/ɪnˈsaɪdər/"]/

Definition

a person who knows a lot about a group or an organization, because they are part of it

In simple words: A person who has special knowledge or information about something.

Examples

  • The situation was described by one insider as ‘absolute chaos’.
  • an insider’s view of the movie industry

Usage notes

Used in contexts like business or politics. Appropriate in formal discussions about leaks or confidences. Avoid in informal settings where slang is preferred.

Grammar pattern

insider + noun (e.g., insider information)

Memory hint

Think of an 'inside' club where only certain people know the secrets.

Collocations

  • insider trading
  • insider information
  • insider knowledge

Synonyms

  • informant
  • participant
  • member
  • associate

Antonyms

  • outsider

Common mistakes

  • 'Insider' is often confused with 'outsider' due to similar sounds.
  • Learners may use 'insider' as a verb, which is incorrect.
  • Some might incorrectly use 'insiders' as a singular noun.