Addalyn is a modern American spelling of Adalyn, itself an elaboration of Adeline and Adela, Germanic names from adal meaning "noble" or "of noble kind". The doubled d echoes Addison and gives the name the nickname Addie. Addalyn hovered just outside the US top 1000 for years, peaking at number 1026 in 2016, and has since slipped to number 2194 in 2025 with 84 births.