The authors agree that this is a Sicilian surname of dialect origin, derived from the term 'mpignùsu, which designates someone punctilious, tenacious or stubborn in his positions. Both likewise agree that its use as a surname would have arisen from a nickname applied to the founding ancestor in allusion to traits of his character.

E. Rossoni specifies that the surname is very rare and locates it specifically in the Catania area, with a presence in Catania and in Gravina di Catania. V. Blunda broadens the meaning of the dialect term and notes that it describes someone who does not give way in a dispute and defends his position obstinately, a detail that enriches the semantic range of the etymon.