Synonyms

standard deviation

American

noun

Statistics.

a measure of dispersion in a frequency distribution, equal to the square root of the mean of the squares of the deviations from the arithmetic mean of the distribution.

standard deviation British

noun

statistics a measure of dispersion obtained by extracting the square root of the mean of the squared deviations of the observed values from their mean in a frequency distribution

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

standard deviation Scientific

/ stăn′dərd /

A statistic used as a measure of the dispersion or variation in a distribution, equal to the square root of the arithmetic mean of the squares of the deviations from the arithmetic mean.

standard deviation Cultural

In statistics, a measure of how much the data in a certain collection are scattered around the mean. A low standard deviation means that the data are tightly clustered; a high standard deviation means that they are widely scattered.

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About sixty-eight percent of the data are within one standard deviation of the mean.

Etymology

Origin of standard deviation

First recorded in 1920–25

Compare meaning

How does standard-deviation compare to similar and commonly confused words? Explore the most common comparisons:

standard deviation vs. standard error

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

standard deviation

If a manager’s or strategy’s alpha is less than 5%, or the standard deviation of return is higher than 20%, then the required length of time is even longer.

From MarketWatch ● Jun. 17, 2026

Their final result brought theoretical predictions and experimental measurements into agreement within less than half a standard deviation.

From Science Daily ● May 19, 2026

Tesla’s average analyst price target is $408 with a 35% standard deviation, implying wider outcomes than other tech giants.

From Barron's ● May 4, 2026

Others criticized Cliffwater’s marketing, especially when it boasted of hedge-fund-like returns with minimal risks, citing industry metrics like Sharpe ratios and standard deviation.

From The Wall Street Journal ● Apr. 1, 2026

No other breed falls outside the standard deviation.

From "The Miscalculations of Lightning Girl" by Stacy McAnulty

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023