Gift of God
Mattisyn is a modern American creative spelling of Madison. It ultimately derives from the English surname meaning 'son of Maud,' with Maud being a Germanic form of Matilda, though it is now almost exclusively associated with the meaning 'gift of God' due to its phonetic similarity to Matthew.
Less common today
Mattisyn isn't in the latest US Top 1000. It last peaked at #7,346 in 2017.
US births per 5-year period, 1990βpresent (SSA data).