F. De Laurentiis proposes that the surname has as its base the nickname derived from the dialectal term crucco, used in the Veneto to refer to the northern populations of Germanic speech.

V. Blunda offers a different interpretation and places it in Sicily: according to this author, the surname is of dialectal origin and comes from the word croccu, which means "hook" or "grapple". The term designated the curved iron used to take cauldrons down from the fire, hold bundles on the beam or handle cheeses during their maturation. As a surname, it could have originated in the trade of the blacksmith specialised in this type of tool, or in a nickname applied to a person with a stooped gait or a twisted character.

The two proposals are independent of each other and point to very different regions and motivations: De Laurentiis links it to the Veneto and to an ethnic-linguistic nickname, while Blunda relates it to Sicily and to a lexical base referring to a domestic or artisanal utensil.