outlier

n. 1. One who does not live where his office, or business, or estate, is. Bentley. [ 1913 Webster ]

2. That which lies, or is, away from the main body. [ 1913 Webster ]

3. (Geol.) A part of a rock or stratum lying without, or beyond, the main body, from which it has been separated by denudation. [ 1913 Webster ]

4. (Statistics) A datum that lies significantly beyond the main cluster of data points on a graph or diagram; -- suggestive of an error in measurement. [ PJC ]