English Noun grey alder (plural grey alders) A tree in the genus Alnus, native to North America and Europe; Alnus incana. Translations Alnus incana Catalan: vern pilós m Esperanto: griza alno Finnish: harmaaleppä (fi) German: Grauerle f Irish: fearnóg liath f Navajo: kʼish Swedish: gråal (sv) c Welsh: gwernen lwyd f Wikiwand - on Seamless Wikipedia browsing. On steroids.