Erynn is a variant of Erin, the poetic Irish name for Ireland.
Erynn is a variant spelling of Erin, one of the most poetically charged names in the English-speaking world. It derives from Éirinn, the dative case of Éire — the Irish name for Ireland itself. In the grammar of classical Irish, the dative "Éirinn" appeared in phrases meaning "to Ireland" or "for Ireland," and it was in this form that poets, particularly during the eighteenth and nineteenth centuries, most often invoked the island in nationalist and romantic verse: "Erin go bragh," meaning "Ireland forever."
The name Erin became a given name largely through this poetic tradition, with Ireland itself — personified as a woman in allegorical literature — lending her country-name to daughters as an act of cultural pride. It flourished in Ireland, then spread through the Irish diaspora to North America, Australia, and Britain. The variant spelling Erynn, with its doubled N and Y, represents a contemporary individualization that became particularly popular from the 1980s onward, softening the name's look while preserving its sound entirely.
Erynn carries the weight of an entire island's history and longing in just five letters. It is a name that has been borne by poets, athletes, and activists, and its association with Ireland's landscape and literary tradition gives it a romantic, elemental quality that has never gone out of fashion — it simply keeps finding new generations who feel it suits them.