MOUNTAIN ASH Meaning of MOUNTAIN ASH in English ■ noun1》 a rowan. [ Sorbus americana (N. America) and related species.] 2》 Austral. a tall eucalyptus tree used for wood. [ Eucalyptus regnans and other species.] Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004