The authors differ on the etymology of this surname. E. De Felice explains it as the transformation into a surname of the personal name Chìrico, with the variant Quirico and the Tuscan form Quilico, and the parallel forms Chirlaco and Ciriaco. These forms continue the Latin names of the Christian era Cyriacus and Quiricus —the latter with the form Qui- by crossing with Quirinus, an old Italic divinity later identified with Romulus—, which are in turn adaptations of the Greek Kyriakós, derived from kyrios, "Lord, God", with the sense of "of the Lord, dedicated to God". De Felice also notes a later and popular variant, Kyrikós, continued in Modern Greek and Byzantine form in the areas of the grika language of Calabria and the Salento.

According to De Felice, the surname spread mainly in the southern peninsula, with greater frequency in southern Calabria and in the Salento area —that is, the southernmost zone of the region of Puglia, in southern Italy—, where the forms of the Greek type Chirlaco, Chiriacò and Chiricò are specific. The forms Chirici and Quilici are, on the other hand, mainly Tuscan.

V. Blunda, for his part, proposes a different etymology: he derives it from the Greek clericòs, "cleric", interpreting it as a nickname applied to an ancestor for his religious trade or for his link to the Byzantine ecclesiastical administration of southern Italy during the medieval period. Blunda circumscribes the surname to Sicily.