Most holy or silver
Arienna is a modern elaboration of Ariadne or Ariana. It likely combines the Greek roots for 'most holy' with the lyrical Latinate suffix '-enna', or may be a variation of the Welsh 'Arian' meaning silver.
Less common today
Arienna isn't in the latest US Top 1000. It last peaked at #7,533 in 2000.
US births per 5-year period, 1990βpresent (SSA data).