Kayin is a distinctive boys' name in United States, ranking #4218 in 2009 with 24 recorded births. The name reached its all-time peak in 2001 with 31 births ranking #2964. Since 1996, the popularity has increased by 71.4%. In 2009, approximately 1 in every 82,638 boys born was named Kayin. FALLING Recent data shows the name is currently falling.