E. Rossoni proposes that this surname would derive from a name or nickname of Greek origin, based on the term koicos, which means "palm leaf". He notes presence in the region of Campania and in a specific area of Palermo.

V. Blunda agrees on the Greek origin, but specifies the etymon as coicos with the sense of "palm tree", identifying it specifically with the date palm of the Mediterranean botanical repertoire. According to Blunda, the term would have motivated the surname by two routes: as a microtoponym applied to the one who came from a plot where that species grew, or as a botanical nickname associated with some trait of an ancestor linked to the tree. His analysis focuses on Sicily.