Son of Maud; high tower
A modern creative spelling of Madison or Madeline. It combines the English surname origin meaning 'son of Maud' with the phonetic influence of Madeline, which refers to Magdala or a 'high tower'.
Less common today
Maddysen isn't in the latest US Top 1000. It last peaked at #14,851 in 2008.
US births per 5-year period, 1990βpresent (SSA data).