Ash tree settlement
A modern spelling variant of Ashton, which derives from Old English elements meaning a town or settlement near ash trees. The 'y' and double 'n' are contemporary stylistic additions to feminize the traditionally masculine surname-turned-given-name.
Less common today
Ashtynn isn't in the latest US Top 1000. It last peaked at #6,189 in 2017.
US births per 5-year period, 1990βpresent (SSA data).