- something that lies outside the main body or group that it is a part of, as a cow far from the rest of the herd, or a distant island belonging to a cluster of islands: The small factory was an outlier, and unproductive, so the corporation sold it off to private owners who were able to make it profitable.
- someone who stands apart from others of his or her group, as by differing behavior, beliefs, or religious practices: scientists who are outliers in their views on climate change.
- an observation that is well outside of the expected range of values in a study or experiment, and which is often discarded from the data set: Experience with a variety of data-reduction problems has led to several strategies for dealing with outliers in data sets.
- a person whose abilities, achievements, etc., lie outside the range of statistical probability.
- Geology. a part of a formation left detached through the removal of surrounding parts by erosion.Compare inlier.
- Obsolete. a person residing outside the place of his or her business, duty, etc.
- an outcrop of rocks that is entirely surrounded by older rocks
- a person, thing, or part situated away from a main or related body
- a person who lives away from his place of work, duty, etc
- statistics a point in a sample widely separated from the main cluster of points in the sampleSee scatter diagram
n.c.1600, “stone quarried and removed but left unused,” from out + lie (v.2). Transferred meaning “outsider” is recorded from 1680s; “anything detached from its main body” is from 1849; geological sense is from 1833.