Save Type Surname (from location) Usage Basque Pronounced Pron. [e.ˈɾa.so](Spanish) [key·simplify] Other Forms FormsErazo, Heraso, Erauso Meaning & History Habitational name of uncertain etymology, possibly derived from Basque iratze "fern" and the abundance suffix -so. Coincides with the Basque word meaning "attack, charge, assault".