Gracious
Jahnia is a modern American creation, likely a rhythmic blend of the Hebrew prefix 'Jah' (referring to Yahweh) and the suffix 'nia'. It is often interpreted as a variant of Jane or John, carrying the traditional meaning of divine favor.
Less common today
Jahnia isn't in the latest US Top 1000. It last peaked at #5,065 in 2003.
US births per 5-year period, 1990βpresent (SSA data).