EUPHONIUM Meaning of EUPHONIUM in English [ ju:'fəʊnɪəm ]■ noun a valved brass musical instrument of tenor pitch, resembling a small tuba.OriginC19: from Gk euphōnos 'having a pleasing sound' + -ium . Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004