The authors agree that this surname has a Germanic root. E. Rossoni considers it characteristic of the Romagna, with the greatest concentration in Cesena and a significant presence in Ravenna, Forlì and Cesenatico. He notes that it derives, directly or through diminutive forms, from the medieval name of Lombard origin Maraldus, documented in the 10th century in a deed of sale. The variant Maraldino appears to be unique, while Maraldo, much rarer, appears linked to the Pordenone area, especially to the locality of Cavasso Nuovo.

F. De Laurentiis proposes a compositional reading: the surname would be formed from the personal elements Mara and Aldo, read mainly as "old man who commands", although it could also take on the sense of "unhappy or afflicted old man".

V. Blunda considers it a surname with a presence in Sicily and derives it from the Germanic compound marah-alda, formed by marah ("horse", "mount") and alda ("old", "wise", "aged woman"), with the sense of "old woman of the horse" or "wise woman of the horse". He notes that marah is the same root as the English mare and that it appears in numerous European anthroponyms linked to the horse as a symbol of prestige in ancient Germanic culture.