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

The system draws on data from devices like the Galaxy Watch and Galaxy Ring to establish a personal baseline, then looks for subtle deviations linked to early dementia research. —Kurt Knutsson, FOXNews.com, 8 Jan. 2026

Though red meat is included on the list of animal proteins the new guidelines recommend — a deviation from previous guidance — experts suggest eating no more than a few servings weekly. —Kristen Rogers, CNN Money, 8 Jan. 2026

During that period, sociologists viewed illness mostly as a deviation from normal functioning leading to impairments that require treatment. —Jennifer Singh, The Conversation, 8 Jan. 2026

This followed a dizzying number of deviations by Greene from the party line, dating back to early summer—foremost were her very public calls for the Justice Department to release the Epstein files. —Charles Bethea, New Yorker, 5 Jan. 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

• abdication
• aberration
• abjuration
• abnegation
• abrogation
• acceptation
• acclamation
• acclimation
• accusation
• activation
• actuation
• acylation

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