Supplanter
A modern American blended name, likely combining the traditional Hebrew name Jacqueline with the popular suffix -lyn. It shares the etymological root of Jacob, referring to one who follows or replaces another.
Less common today
Jacilyn isn't in the latest US Top 1000. It last peaked at #6,119 in 1995.
US births per 5-year period, 1990βpresent (SSA data).