The authors agree that the surname has its origin in the Sicilian dialect and refers to the word gèrfu / ggerfu, meaning "bitter, unripe, harsh". F. Miranda adds, relying on the Sicilian Vocabulary of Piccitto, that the term is also applied to the plant that, on reaching maturity, produces seed, or to the one that withers due to causes such as frost.

V. Blunda interprets the surname as arisen from a nickname of a behavioural or agricultural character: it could designate a person of harsh or gruff manner, or be applied to ungrateful lands. Blunda also records the form Lo Gerfo as an independent surname with an identical etymon, although both are treated as distinct entries. Miranda, for his part, documents the presence of the surname in some twenty-five comuni scattered in several regions: Sicily —with the most numerous nucleus, distributed among the provinces of Palermo, Trapani, Enna, Agrigento, Caltanissetta and Catania—, as well as Piedmont, Lazio and Calabria.