1 : a person whose residence and place of business are at a distance.
His house was a place of refuge for outliers.
2 : something (such as a geological feature) that is situated away from or classed differently from a main or related body.
The island is an outlier on the southeast side of the archipelago.
3 : a statistical observation that is markedly different in value from the others of the sample Values that are outliers give disproportionate weight to larger over smaller values. Typically, the outliers indicate new information about the experimental design parameters.