Kailyn is a modern American coinage, a variant of Kaylin and Kaelyn that joins the Kay or Kai sound to the ending -lyn; through Kay it is often linked to Katherine, "pure", though the name is really a creation of the late 20th century. Kailyn ranked number 593 in 2000, peaked at number 397 in 2011, was still number 659 in 2015 and ranks 1825 in 2025 after leaving the top 1000.