deviation

noun

de·​vi·​a·​tion ˌdē-vē-ˈā-shən 

: 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

deviationism

ˌdē-vē-ˈā-shə-ˌni-zəm 

noun

deviationist

ˌdē-vē-ˈā-sh(ə-)nist 

noun or adjective

Synonyms of deviation

• departure
• detour
• divergence
• deflection

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.

Recent Examples on the Web

Pilot deviations accounted for 62% of incursions from 2021 through 2025. — Amalia Roy, FOXNews.com, 24 June 2026

When the complex was being constructed, there were deviations from the building’s original design, contributing to structural weaknesses, the report said. — Aaron Leibowitz, Miami Herald, 23 June 2026

At the same time, the city began to pressure Cal Coast to re-zone the golf course for another 500 homes, a deviation from the original development, Miller said. — Chase Hunter, Mercury News, 23 June 2026

In 2023 a collaboration of radio astronomers reported tiny deviations in the timing of these flashes from dozens of pulsars in the Milky Way. — Joseph Howlett, Scientific American, 18 June 2026

Word History

Etymology

see deviate entry 1

First Known Use

15th century, in the meaning defined above

Phrases Containing deviation

• mean deviation
• mean square deviation
• standard deviation

Rhymes for deviation

• ablation
• aeration
• bination
• carnation
• cassation
• castration
• causation
• centration
• cessation
• cetacean
• chelation
• citation

Kids Definition

deviation

noun

de·​vi·​a·​tion ˌdē-vē-ˈā-shən 

: an act or instance of deviating: as

a

: the difference found by subtracting some fixed number (as the arithmetic mean of a series of statistical data) from any item of the series

b

: noticeable difference from accepted standards (as of behavior or morals)

Medical Definition

deviation

noun

de·​vi·​a·​tion ˌdē-vē-ˈā-shən 

: 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