insider

plural insiders

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

   Near-synonyms: initiate, old hand, habitué

   4 more examples

   Heavy losses were sustained in Simms Petroleum, which took a greater toll from supposed "Wall Street insiders" than from the general public.

   1923 July 2, “‘Big Board’ Failures”, in Time

   He is also an astute ANC insider who spent ten years on Robben Island alongside Nelson Mandela and the other “grandees” of the movement.

   2007 December 19, Jonathan Clayton, “Profile: Zuma charmed wives and a nation”, in Times of London, UK

   In a thread called “Calm Before the Storm”, and in subsequent posts, Q established his legend as a government insider with top security clearance who knew the truth about a secret struggle for power involving Donald Trump, the “deep state”, Robert Mueller, the Clintons, pedophile rings, and other stuff.

   2018 July 31, Julia Carrie Wong, “What is QAnon? Explaining the bizarre rightwing conspiracy theory”, in The Guardian

   That, as one of my more sceptical industry insiders put it, is because there is a reluctance to commit funds to any of these plans - and we can put the blame firmly on the fact that HS2 is eating up £7bn per year for the whole term of this parliament.

   2026 March 18, Christian Wolmar, “Wales sets example with long-term rail strategy”, in RAIL, number 1057, page 43

   Synonyms: initiate, old hand, habitué · Antonyms: outsider

2. A person who is within an enclosed space.

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

   1849, Herman Melville, chapter 33, in Redburn: His First Voyage. […], 1st American edition, New York, N.Y.: Harper & Brothers, […], →OCLC