[ dee-vee-ey-shuh n ]
/ ˌdi viˈeɪ ʃən /


the act of deviating.
departure from a standard or norm.
Statistics. the difference between one of a set of values and some fixed value, usually the mean of the set.
Navigation. the error of a magnetic compass, as that of a ship, on a given heading as a result of local magnetism.Compare variation(def 8).
  1. Also called deflection. the bending of rays of light away from a straight line.
  2. angle of deviation.
departure or divergence from an established dogma or ideology, especially a Communist one.

Origin of deviation

1375–1425; late Middle English (< Middle French) < Medieval Latin dēviātiōn- (stem of dēviātiō), equivalent to Late Latin dēviāt(us) (see deviate) + -iōn- -ion


de·vi·a·to·ry [dee-vee-uh-tawr-ee, -tohr-ee] /ˈdi vi əˌtɔr i, -ˌtoʊr i/, de·vi·a·tive, adjectivenon·de·vi·a·tion, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for deviation

British Dictionary definitions for deviation

/ (ˌdiːvɪˈeɪʃən) /


an act or result of deviating
statistics the difference between an observed value in a series of such values and their arithmetic mean
the error of a compass due to local magnetic disturbances
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

Medicine definitions for deviation

[ dē′vē-āshən ]


A turning away or aside from a normal course.
An abnormality.
Deviant behavior or attitudes.
The difference, especially the absolute difference, between one number in a set and the mean of the set.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for deviation

[ dē′vē-āshən ]

The difference between one number in a set and the mean of the set.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.