n.1 a deviating, digressing. b an instance of this.
2 Polit. a departure from accepted (esp. Communist) party doctrine.
3 Statistics the amount by which a single measurement differs from the mean.
4 Naut. the deflection of a ship's compass-needle caused by iron in the ship etc.
Phrases and idioms:
standard deviation Statistics a quantity calculated to indicate the extent of deviation for a group as a whole.
Derivatives:
deviational adj. deviationism n. deviationist n.
Etymology: F d{eacute}viation f. med.L deviatio -onis (as DEVIATE)