Noble kind
Adallyn is a modern American coinage, likely created by blending the Germanic root 'Adal' (meaning noble) with the popular 'lyn' suffix. It follows the trend of names like Adeline and Madelyn while offering a more unique phonetic profile.
Less common today
Adallyn isn't in the latest US Top 1000. It last peaked at #10,048 in 2016.
US births per 5-year period, 1990βpresent (SSA data).