Dioguardi (Italian) comes from Italian Dio, from Latin Deus, from Latin dẹ̄vos, from Old Latin deivos, from Proto-Italic deiwos, from Proto-Indo-European deywós, from Proto-Indo-European dyew- — to be bright; sky, heaven.
Ancestry of “Dioguardi”, step by step
Dioguardi traces back through two separate lines of ancestry.