Great, magnificent, or venerable
Austynn is a modern creative spelling of Austin, which originated as a medieval contracted form of the Latin name Augustus. It carries the same meaning of being exalted or majestic, but the 'y' and double 'n' suffix give it a contemporary, feminine flair.
Less common today
Austynn isn't in the latest US Top 1000. It last peaked at #4,970 in 2015.
US births per 5-year period, 1990βpresent (SSA data).