Lain is a unisex given name of Scottish origin, derived from the Scottish surname "Laing," which itself originated from the Old French name "Lanier," meaning "fencer" or "glovemaker." The name Lain gained popularity in the late 20th century and has since been used for both boys and girls. It is often associated with the popular anime series "Serial Experiments Lain," created by Ryoki Takusaki, which contributed to its increase in popularity among younger generations worldwide.
The name Lain experienced a notable increase in popularity from the late 90s to early 2000s, peaking at 25 births in 2011 and 22 births in 2012. However, it has since declined, with only 8 births recorded in 2023.