Lain is a distinctive boys' name in United States, ranking #5040 in 2001 with 15 recorded births. The name reached its all-time peak in 2011 with 25 births ranking #4053. Since 1996, the popularity has increased by 36.4%. In 2001, approximately 1 in every 129,522 boys born was named Lain. RISING Recent data shows the name is currently rising.