The authors agree that the surname derives from the Greek term rachis, which designates the spinal column or the back, and that it would have arisen as a nickname applied to a bearer who at birth presented the back first, complicating the delivery. F. Miranda specifies that the surname constitutes the transformation of that nickname into a surname, and adds two further hypotheses: it could derive from the Arabic name Rachid, very diffused in the Islamic world and introduced into Sicily during the Muslim domination, or else from the Greek term ραχη, with the sense of "mountain" and, by extension, "mountaineer," according to D. Macris. Miranda also notes that the first documented bearer would be the monk Saint Elias of Enna, born in Enna around 822–823 and died in Thessalonica on 17 August 903, whose given name was Giovanni Rachites (Ἰωαννης Ραχιτης).

As to its geographic distribution, the authors agree that the surname is typical of eastern Sicily, with a presence concentrated in the Catania area, and also in the Messina and Syracuse areas. Miranda adds smaller nuclei in the Palermo, Ragusa and Trapani areas. E. Rossoni further notes the variant Racito, practically unique, native of the same localities and considered probably a dialectal form of the main surname.