Gracious
Gianah is a modern variant of Gianna, which is the Italian diminutive of Giovanna. It ultimately derives from the Hebrew name Yochanan, meaning 'God is gracious.' This spelling adds a soft 'h' ending, giving it a more contemporary American feel.
Less common today
Gianah isn't in the latest US Top 1000. It last peaked at #8,435 in 2009.
US births per 5-year period, 1990βpresent (SSA data).