E. Rossoni and E. Costantini agree that the surname derives from the feminine personal name Agata.

E. Rossoni notes that it comes from a modification of the name Agata, first transformed into Aghjta and then into Ajta and Aita. He adds that it can also be related to the term aita ("help"), as a nickname given to especially generous people.

E. Costantini agrees, indicating that it comes from the feminine personal name Agata, probably through the intermediate form Aghita. He notes that the first known attestation is from 1508 with Zuan d'Ayta de Buya.

V. Blunda offers a different interpretation, noting that it is a Sicilian surname of Greek origin, linked to the zoological and symbolic lexicon of the Hellenic world. It derives from the etymon Aètas, meaning "eagle". He explains that the bird was a symbol of power and sovereignty both in Greek mythology —it was the sacred animal of Zeus— and in Byzantine heraldry, where the double-headed eagle became the imperial emblem. The surname may have arisen as a nickname applied to an ancestor for his physical features, his piercing gaze or his haughty bearing.