1 : an action, behavior, or condition that is different from what is usual or expected [count] ▪ There have been slight deviations in the satellite's orbit. ▪ Having juice instead of coffee was a deviation from his usual routine. [noncount] ▪ The pattern's deviation from the norm is significant. ▪ The book discusses sexual deviation [=deviance] in serial killers. 2 [count] technical : the difference between the average of a group of numbers and a particular number in that group





