More info about the name "Gianna"
Gianna is a diminutive of Giovanna. Giovanna originates in Hebrew language and means "God is merciful". It is a feminine form of Giovanni, Italian form of John, ultimately derived from Hebrew Yochanan. It is related to other feminine given names derived from Yochanan, such as Jane, Joan, etc. Giovanna of Italy was the last Empress of Bulgaria. In the United States the English variants of the name are more popular.