The surname has multiple independent ancestral stocks (ceppi), arising in different regions with no direct connection between them. All three scholars consulted agree on a Germanic origin, though they approach it from different angles.

R. Brondolo interprets the surname as a diminutive of (Rai)mondo, a given name of Germanic origin. F. Miranda builds on this view and proposes that the surname may have arisen as an apocopated form — that is, through the loss of the initial syllable — of compound Germanic names such as Gis-mondo, Rai-mondo, or Ed-mondo, making it a surname of patronymic type. This is consistent with the position of Surnames in Italy, which records the surname as deriving from the given name Edmondo.

V. Blunda offers a more precise etymological grounding, tracing the surname to the personal name Munda, linked to the Germanic root munda, meaning "protection" or "legal guardianship." Blunda also cautions that the popular association with the Italian mondo ("world, universe") is a false etymology: that noun descends from the Latin mundus, which is unrelated to the Germanic anthroponym.

Miranda additionally proposes a secondary line of origin: the adjective mondo ("clean, honest, luminous") used as a byname, sometimes bestowed by ecclesiastics on foundling children. Miranda identifies the main areas of presence as Piedmont, Sicily, and Campania, with further specific, localized areas in Lombardy, Friuli-Venezia Giulia, Veneto, Emilia-Romagna, Liguria, and Lazio.