E. Rossoni proposes that the surname could derive from the term nicchio —the snail, emblem of one of the contrade of Siena and of the corporation of potters—, extended by association to the trade of potter. This hypothesis places it in the Arezzo, Siena and Perugia areas, where the surname is very infrequent.

V. Blunda offers a different etymology for the Sicilian sphere: the surname would come from the dialect word nìcchiu, with the meaning "foolish, simple, dim", a term describing a person of limited understanding and slow reactions. In this case, the surname would have arisen as a nickname of a behavioural character, of pejorative motivation, which in time was transmitted hereditarily within the family.

The two proposals are independent of each other and point to distinct geographical and semantic origins: one linked to central Italy —with reference to the artisan world and to Sienese communal symbolism—, and the other proper to Sicily, rooted in the popular dialect lexicon.