Dillen, a unisex name pronounced DIL-en (/ˈdɪlən/), embraces a contemporary twist on the Celtic Dillon and Welsh Dylan traditions. With roots in the Irish Ó Duilleáin—literally “descendant of Duilleán”—and the Welsh dy (“great”) plus llen (“sea”), it conjures both ancestral loyalty and the vast, ever-shifting horizon of the ocean. Though it has never stormed the summit of the popularity charts, Dillen’s steady placement in the mid-900s of U.S. birth rankings over the past thirty years attests to its quietly steadfast allure. It’s the kind of name that prefers a subtle entrance—rewarding analytical minds and those with a taste for dry wit—offering individuality as effortless yet memorable as a seabird skimming a misty coastline.