What does Gianna mean?
Italian feminine form of Gianni/Giovanni (John), from Hebrew 'Yochanan' meaning 'Yahweh is gracious / God is gracious'.
What does Aria mean?
From the Italian word 'aria', meaning 'air' and, in music, a solo melody or song. An identical-looking name also exists in Hebrew (related to 'aryeh', lion) and Persian, but the modern popularity rests on the Italian 'melody' sense.