Gianna sits next to 4 phonetic neighbors — Joanna, Giovanna, and Diana are the closest matches by sound. Most share Gianna's Italian-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"God is gracious"
"child of light"
"flat tropical grassland"
"born of Juno, goddess of marriage"
"grace, favor"
"peace, fruitfulness"
"exalted, sublime"
"hay meadow, hay clearing"
"seller of scarlet cloth"
"glory, elevation (from mountain name)"
"heroine of God"
"sun, sunshine"
"night rain"
"Pacca's town"
"chief leader"
"rival, striving"
"lunar goddess, moonlight"
"bright, shining light"
"crowned one"
"gift of birth"
Similar sound: These names share phonetic patterns with Gianna — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Italian origins, giving them the same cultural heritage as Gianna.
Rhythm: Gianna is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.