E. Rossoni notes that the surname could derive from two different sources: on the one hand, from dialectal modifications of diminutive forms of the name Ricardo, Accardo or similar, documented in Naples in 1363; on the other, from nicknames originating in the Late Latin word cardellus, meaning "goldfinch". Rossoni places its presence mainly in Sicily, above all in the western area and in the Palermo area, with presence also in Rome, in the Latina area, in the Caserta area, in the Naples area and in the Salerno area.

V. Blunda proposes a different etymology of strictly Sicilian character: the surname would come from the dialectal word cardèdda, which designates the sow thistle or cicerbita, a wild plant with edible leaves much used in the rural cooking of the island. For Blunda, the surname would have arisen as a reference to the trade of the one who gathered these wild vegetables or as a nickname for the one who habitually consumed them, which places it within the group of surnames of phytonymic origin.

Both proposals are not necessarily mutually exclusive: the Late Latin form cardellus designated the goldfinch, but in Sicilian dialectal speech the same root could have been adapted to also name the plant, which would explain the divergence between the two interpretations.