Jailyn is a modern American coinage that pairs the popular Jay sound with the ending -lyn, which comes from the Welsh word for "lake" and has been attached to countless American girls' names. It is a sister spelling of Jaylin and Jaelyn and has no traditional meaning of its own. Jailyn was in the top 1000 at number 986 in 2000, peaked at number 879 in 2002 and has gradually declined since, to number 1556 in 2015 and number 2469 in 2025 with 72 girls.