Woman from Magdala or high tower
Maddilyn is a modern Americanized spelling of Madeline. It traces back to the Greek name Magdalene, referring to Mary Magdalene from the town of Magdala, which itself is derived from a Hebrew word meaning tower.
Less common today
Maddilyn isn't in the latest US Top 1000. It last peaked at #1,983 in 2016.
US births per 5-year period, 1990βpresent (SSA data).