- 1. A turning away or aside from the normal point or course. 2. An abnormality. 3. In psychiatry and the behavioral sciences, a departure from an accepted norm, role, or rule. SYN: deviance. 4. A statistical measure representing the difference between an individual value in a set of values and the mean value in that set. [L. devio, to turn from the straight path, fr. de, from, + via, way]- axis d. deflection of the electrical axis of the heart to the right or left of the normal. SEE ALSO: left axis d., right axis d., axis. SYN: axis shift.- conjugate d. of the eyes 1. rotation of the eyes equally and simultaneously in the same direction, as occurs normally; 2. a condition in which both eyes are turned to the same side as a result of either paralysis or muscular spasm.- dissociated horizontal d. a tendency often associated with repaired congenital esotropia in which an eye abducts when it is covered, in violation of Herring law.- dissociated vertical d. a tendency often associated with congenital esotropia, in which an eye elevates, abducts, and extorts when covered, in violation of Herring law.- immune d. SYN: split tolerance.- d. to the left SYN: shift to the left (1).- left axis d. a mean electrical axis of the heart pointing to −30° or more negative. See hexaxial reference system.- primary d. the ocular d. seen in paralysis of an ocular muscle when the nonparalyzed eye is used for fixation.- d. to the right SYN: shift to the right (1).- right axis d. a mean electrical axis of the heart pointing to the right of +90°. See hexaxial reference system.- secondary d. ocular d. seen in paralysis of an ocular muscle when the paralyzed eye is used for fixation.- sexual d. a sexual practice that is biologically atypical, considered morally wrong, or legally prohibited. See bestiality, pedophilia. SYN: sexual perversion.- skew d. a hypertropia in which the eyes move in opposite directions equally; an acquired hypertropia, often fairly comitant, not fitting the characteristic pattern of trochlear nerve damage or of ocular muscle abnormality; often due to a brainstem or cerebellar lesion.- standard d. (SD, σ) 1. statistical index of the degree of d. from central tendency, namely, of the variability within a distribution; the square root of the average of the squared deviations from the mean. 2. a measure of dispersion or variation used to describe a characteristic of a frequency distribution.
* * *de·vi·a·tion .dē-vē-'ā-shən n an act or instance of diverging from an established way or in a new direction: asa) evolutionary differentiation involving interpolation of new stages in the ancestral pattern of morphogenesisb) noticeable or marked departure from accepted norms of behavior
* * *n.1. (in ophthalmology) any abnormal position of one or both eyes. For example, if the eyes are both looking to one side when the head is facing forwards, they are said to be deviated to that side. Such deviations of both eyes may occur in brain disease. Deviations of one eye, such as dissociated vertical deviation, come into the category of squint (see strabismus).
* * *de·vi·a·tion (de″ve-aґshən) [L. deviare to turn aside] 1. a turning away from the regular standard or course. 2. in ophthalmology, strabismus. 3. in statistics, the difference between a sample value and the mean.
Medical dictionary. 2011.