* παράβασις (parabasis): This means "transgression," "violation," or "deviation." It implies a departure from a rule, law, or standard. It's a good choice if the departure is considered wrong or undesirable.
* ἀνωμαλία (anōmalia): This means "anomaly," "irregularity," or "abnormality." It emphasizes the unusual or unexpected nature of the departure. It's suitable when the departure is simply different, not necessarily bad.
* ἀποκλίνω (apoklinō): This is a verb meaning "to deviate," "to diverge," or "to depart." It describes the *act* of departing from something, rather than the departure itself. You would use this in a sentence like "The data *deviated* from the expected norm."
* ἐκτροπή (ektropē): This means "deviation," "departure," or "diversion." It's similar to *parabasis* but perhaps slightly less strongly implies wrongdoing.
The best choice will depend on context. If you can provide the specific context in which you need to use the word, I can help you choose the most appropriate Greek term.