Gracious
Chianna is a modern American creation, likely formed by blending the prefix 'Chi-' with the classic name Anna. It is often interpreted as a variant of Gianna, the Italian diminutive of Giovanna, which shares the Hebrew root meaning 'God is gracious'.
Less common today
Chianna isn't in the latest US Top 1000. It last peaked at #7,236 in 1997.
US births per 5-year period, 1990βpresent (SSA data).