The surname Amarù presents a significant etymological divergence among various specialists in Sicilian onomastics. On the one hand, Giovanni Battista Alessio proposed a derivation from the Late Greek Almurodes, with the sense of "brackish" or "salty", a hypothesis linked to the deep Greek substrata present in Sicily and southern Italy. Alessio was one of the great Italian specialists in etymology and southern toponomastics, as well as co-author of the monumental DEI – Dizionario etimologico italiano together with Carlo Battisti.

By contrast, Girolamo Caracausi, in his Dizionario onomastico della Sicilia, considered a French origin more likely, relating the surname to the form Amarrou. Both interpretations are difficult to reconcile, since they refer to different linguistic traditions —one Greek-Byzantine and the other Franco-Romance—, constituting a clear example of genuine etymological divergence within the studies on Sicilian surnames.

References cited by F. Miranda:

• Alessio, G. B. (1950–1957). Dizionario etimologico italiano (with C. Battisti, 5 vols.). Barbèra.
• Caracausi, G. (1993). Dizionario onomastico della Sicilia: Repertorio storico-etimologico di nomi di famiglia e di luogo (2 vols.). Centro di Studi Filologici e Linguistici Siciliani.