Hello. The French substantive damoiseau and the Italian donzello share the same original meaning (i.e someone who was, in the Middle Age, serving as a would-be Knight), as well as the same etymo fromLatin dominicellus. They both are, still today although not very frequently, registered family names in France as well as in Italy, respectively. Among the variants one can also find Damoiseaux and Donzelli. The latter seems to be a plural, but it could also be a patronymic latinlike genitive. As for the former, according to "about.com Genealogy", the suffix -eau is already a patronymic: little son of. I do not understand the further addition of the plural suffix X. Thank you for your patience.