Kayin is a distinctive boys' name in United States, ranking #3844 in 2007 with 27 recorded births. This places Kayin in the top 27% of ranked US boys' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2001 with 31 births ranking #2964. Since 1996, the popularity has increased by 92.9%. In 2007, approximately 1 in every 76,861 boys born was named Kayin. FALLING Recent data shows the name is currently falling.