say it: dee-vee-AY-shuhn
deviation is a noun meaning "a variation that deviates from the standard or norm". It carries 5 recorded senses.
a variation that deviates from the standard or norm
“the deviation from the mean”
the difference between an observed value and the expected value of a variable or function
statistics
the error of a compass due to local magnetic disturbances
deviate behavior
a turning aside (of your course or attention or concern)
“a diversion from the main highway”
“a digression into irrelevant details”
“a deflection from his goal”
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for deviation come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.