E. Rossoni proposes that the surname would derive from a modification of the Italo-Germanic name Ghino, or from a variation of the Germanic Wido (Guido). According to Rossoni, the surname shows isolated pockets on the boundary between the provinces of Rovigo and Mantua, and another in the Turin area. The form Ghiotto, for its part, would be typical of the Vicenza area, with a possible additional presence in the Genoa area.

F. De Laurentiis links it specifically to Guidi, a form derived from the name Guido, and notes that its development reflects a phonetic process proper to north-western Italy, with probable influence from the French name Guy. De Laurentiis specifies that the Germanic name Wito —relatable to Gothic widus ("wood, forest") or to Old High German wit ("distant"), and regarded as the initial element of a compound name according to the usual pattern of Germanic onomastics— entered Italy with the Lombards and was adapted to local phonetic conditions.