outlier

American  

[out-lahy-er] / ˈaʊtˌlaɪ ər /

noun

1. something that lies outside the main body or group that it is a part of, such 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.

2. someone who stands apart from other members of a group, such as by differing behavior, beliefs, or religious practices.

   There are a few scientists who are outliers in their views on climate change.

   Synonyms:

   outsider, heretic, iconoclast, dissenter, dissident, bohemian, eccentric, original, maverick, nonconformist

3. Statistics.

   1. 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.

   2. a person whose abilities, achievements, etc., lie outside the range of statistical probability.

4. Geology. a part of a formation left detached through the removal of surrounding parts by erosion.

5. Obsolete. a person residing outside the place of their business, duty, etc.

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outlier British  

/ ˈaʊtˌlaɪə /

noun

1. an outcrop of rocks that is entirely surrounded by older rocks

2. a person, thing, or part situated away from a main or related body

3. a person who lives away from his place of work, duty, etc

4. statistics a point in a sample widely separated from the main cluster of points in the sample See scatter diagram

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Etymology

Origin of outlier

First recorded in 1600–10; out- + lier

Explanation

In statistics an outlier is a piece of data that is far from the rest; think of a graph with dots, where most dots are clustered together in the middle, but one dot, the outlier, is at the top. Think of an outlier as an outsider. An outlier refers to anything that strays from, or isn’t part of, the norm. If you like to sleep in a tent in the backyard while your neighbors and family sleep in their beds, you’re probably an outlier. You may also be an outlier if you have to travel far to your job. In geology, rock that is separated from another rock formation is called an outlier.

Example Sentences

Spreading your equity portfolio across sectors and a variety of factors can help improve the odds of capturing gains when the outlier stocks start outperforming.

From MarketWatch • Apr. 14, 2026

Then there’s wind. Amazon.com founder Jeff Bezos’ 410-foot sailing yacht Koru —estimated cost: $500 million—remains an outlier.

From Barron's • Apr. 11, 2026

“In the quickly expanding universe of cases involving sanctions for the misuse of artificial intelligence, this case is a notorious outlier in both degree and volume,” Clarke wrote.

From Los Angeles Times • Mar. 27, 2026

But somehow, I have managed to defy the odds, becoming the rare outlier to not only protect my job from the A.I. monster’s bite but profit from its terrors.

From Slate • Mar. 20, 2026

The fourth member of the group, Don Snedeker, was also, in his own way, an outlier.

From "Drama High" by Michael Sokolove

Related Words

• aberration
• deviation
• eccentricity
• exception
• oddity