Unknown; possibly a modern elaboration of Maya or Mia.
Myonna is a modern American name with no singular established etymology. It is likely a creative elaboration of the popular names Mia or Maya, or a variation of the name Mionna, often used within African American communities to create a unique, melodic sound.
Less common today
Myonna isn't in the latest US Top 1000. It last peaked at #5,419 in 2005.
US births per 5-year period, 1990βpresent (SSA data).