Kaylynn is a modern American blend of Kay, originally a short form of Katherine and usually read as "pure", with the ending -lynn, which goes back to the Welsh word for "lake". It belongs to the large family of Kay- names that flourished in the 1990s and 2000s. Kaylynn stood at number 750 in 2000, peaked at number 513 in 2009 and has since fallen to number 1576 in 2025.