E. Rossoni proposes that the surname derives from a nickname originated in the Logudorese Sardinian term ganga, meaning "throat", possibly applied to someone considered very greedy. According to Rossoni, the surname presents a main trunk in the Nuoro area and another of lesser entity, probably secondary, in Rome.

V. Blunda offers a different etymology, of Sicilian base. According to this author, the surname comes from the dialectal word ànga, which designated the molar or grinding tooth, that is, the posterior dental pieces in charge of mastication. The form ganga would result from a consonantal prosthesis characteristic of Sicilian. As a surname, it would have arisen from a descriptive nickname applied to a person with prominent teeth or with some notorious peculiarity in the molars. Blunda links it with other surnames of the same semantic field, such as Gangarella, Gangarossa and Gargia, all referring to the region of the mouth and the jaw.

Both proposals agree that the surname was born from a nickname of physical base, although they differ in the language of origin —Logudorese Sardinian for Rossoni, Sicilian for Blunda— and in the part of the body alluded to: the throat in one case, the teeth in the other.