Prognostication

From Epicurus Wiki

Prognostication, or divination [προσημείωσις] was a widespread practice among ancient Greeks and Romans. Common types of divination involved watching the flight of oionoi (omens -- probably ravens), sacrificing a bird and looking into its entrails, studying the direction from which lightning struck, and many other natural "signs" that were allegedly predictive of the future.

Epicurus and, far more extensively, Lucretius discarded such beliefs as superstition.