Kayin is a distinctive boys' name in United States, ranking #3910 in 2003 with 22 recorded births. The name reached its all-time peak in 2001 with 31 births ranking #2964. Since 1996, the popularity has increased by 57.1%. In 2003, approximately 1 in every 89,785 boys born was named Kayin. FALLING Recent data shows the name is currently falling.