Supplanter; son of James
A modern patronymic variant of James, which ultimately derives from the Hebrew name Jacob. It signifies one who follows or replaces another, often interpreted as 'supplanter'.
Less common today
Jamesen isn't in the latest US Top 1000. It last peaked at #4,167 in 2017.
US births per 5-year period, 1990βpresent (SSA data).