Son of Maud; or, son of Matthew
Madicyn is a modern creative spelling of Madison. It originated as an English surname meaning 'son of Maud' (a form of Matilda) or 'son of Madde' (a medieval diminutive of Matthew).
Less common today
Madicyn isn't in the latest US Top 1000. It last peaked at #8,735 in 2005.
US births per 5-year period, 1990βpresent (SSA data).