Gaylen is of Scottish origin, derived from the Gaelic 'Gille Eithne', which translates to 'devoted to Saint Ethen'. It is a unisex name, historically used more for males but now occasionally given to females as well.
"The name Gaylen experienced significant popularity spikes from the late 1940s to the early 1950s, with a peak of 94 births in 1949. However, it saw a steady decline thereafter, dropping to as low as 5 births per year between 1982 and 2005."