de·​vi·​a·​tion | \ ˌdē-vē-ˈā-shən How to pronounce deviation (audio) \

Definition of deviation

: an act or instance of deviating: such as
a navigation : deflection of the needle of a compass caused by local magnetic influences (as in a ship)
b mathematics : the difference between a value in a frequency distribution and a fixed number (such as the mean)
c : departure from an established ideology or party line deviation from Communist orthodoxy
d : noticeable or marked departure from accepted norms (see norm sense 2) of behavior

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Other Words from deviation

deviationism \ ˌdē-​vē-​ˈā-​shə-​ˌni-​zəm How to pronounce deviationism (audio) \ noun
deviationist \ ˌdē-​vē-​ˈā-​sh(ə-​)nist How to pronounce deviationist (audio) \ noun or adjective

Examples of deviation in a Sentence

There have been slight deviations in the satellite's orbit. Having juice instead of coffee was a deviation from his usual routine. The pattern's deviation from the norm is significant.
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Recent Examples on the Web

Tailoring the app to an individual might also be important so that its algorithm can detect deviations from that person's normal behavior. Kelly Servick, Science | AAAS, "Suicide attempts are hard to anticipate. A study that tracks teens’ cellphone use aims to change that," 21 Aug. 2019 One notable deviation from the Ruth-Debbie storyline this season involves their relationship, which began to bloom at the very end of season two. Pilot Viruet, Vox, "GLOW season 3 loses some of its trademark fun amid all the bloat," 13 Aug. 2019 This deviation didn't cause too much trouble for anyone until this weekend, when a stream featuring hardcore pornography somehow shot to the top of those Fortnite recommendations. Kyle Orland, Ars Technica, "Twitch backtracks after accidentally showing porn on Ninja’s old page," 12 Aug. 2019 Here’s every deviation the auteur took in Once Upon a Time… in Hollywood. 1. Alexia Fernandez,, "Once Upon a Time in... Hollywood Fact-Checked: What the Movie Gets Right and Wrong," 30 July 2019 My only other deviation from Chris’ recipe is timing. Adam Rapoport, Bon Appétit, "Zucchini Doesn’t Have to Be Watery and Sad," 18 June 2019 In the asexual species, the zero growth value is four or more standard deviations away from the mean, in the downward direction — a circumstance that has a probability of 0.000031671, which will occur once in about 31,574 generations on average. Quanta Magazine, "Solution: ‘Why Are There Two Sexes?’," 28 July 2017 Any deviation from my scripted trajectory warrants a worried phone call or text message. Boone Ashworth, WIRED, "The Terrible Anxiety of Location Sharing Apps," 28 July 2019 Physicists require a 5-sigma deviation from their expectations, equivalent to flipping 75 heads in 100 tosses (the odds of which are less than one in a million), to claim the discovery of a real effect. Quanta Magazine, "‘Penguin’ Anomaly Hints at Missing Particles," 20 Mar. 2015

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'deviation.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of deviation

15th century, in the meaning defined above

History and Etymology for deviation

see deviate entry 1

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Statistics for deviation

Last Updated

27 Aug 2019

Look-up Popularity

Time Traveler for deviation

The first known use of deviation was in the 15th century

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More Definitions for deviation



English Language Learners Definition of deviation

: an action, behavior, or condition that is different from what is usual or expected
technical : the difference between the average of a group of numbers and a particular number in that group


de·​vi·​a·​tion | \ ˌdē-vē-ˈā-shən How to pronounce deviation (audio) \

Medical Definition of deviation

: an act or instance of diverging from an established way or in a new direction: as
a : evolutionary differentiation involving interpolation of new stages in the ancestral pattern of morphogenesis
b : noticeable or marked departure from accepted norms of behavior

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Comments on deviation

What made you want to look up deviation? Please tell us where you read or heard it (including the quote, if possible).


formidable, illustrious, or eminent

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