Gracious
Shiann is a modern phonetic variant of the Irish name Sian, which is the Welsh form of Jane. It ultimately derives from the Hebrew name Yochanan, meaning 'God is gracious'. While it shares a sound with the name Cheyenne, its etymological roots are distinct.
Less common today
Shiann isn't in the latest US Top 1000. It last peaked at #1,317 in 1998.
US births per 5-year period, 1990βpresent (SSA data).