Definition of "outlier"

outlier

/ˈaʊtˌlaɪə(ɹ)/

noun
plural outliers
1. A person or thing situated away from the main body or outside its proper place.
  Quotations
  Observing as an outlier from Scotland, Hynes sums up the industry problem: "The conversation we've had for this article is really about creating an environment in which better decisions can be taken, isn't it?
  2023 November 1, Paul Clifton, “One account for the UK railway”, in RAIL, number 995, page 47
2. An exception.
3. (geology) A part of a formation separated from the rest of the formation by erosion.
4. (statistics) A value in a statistical sample which does not fit a pattern that describes most other data points; specifically, a value that lies 1.5 IQR beyond the upper or lower quartile.