E. Rossoni places this surname in the Treviso area, in Veneto, and proposes that it would derive from a dialect nickname. He analyses the form as a compound of Marco and degàn, where degàn or degàni is itself a Venetan surname meaning in general terms "dean", although among the Venetian degani it designated specifically the ministerials, riverside officers or local administrators.

F. De Laurentiis offers a different reading: the base would be the Venetan nickname mardegan, derived from the Hebrew name Mordekay, with the sense of "clumsy and ignorant person". This reading connects the surname with the tradition of mocking nicknames taken from given names, in this case of biblical origin.