lineal/ˈlɪnɪəl; `lɪnɪəl/ adj[usu attrib 通常作定语]1 (fml 文) in the direct line of descent 直系的; 嫡系的 a lineal heir to the title 该头衔的直系承袭人.2 = linear.
牛津英汉双解词典