lineal

形容词 lineal:

1. in a straight unbroken line of descent from parent to child
   同义词：direct
2. arranged in a line

lin.e.al

adj.Abbr. lin.（形容词）缩写 lin.
Belonging to or being in the direct line of descent from an ancestor.
直系的：属于或成为祖先的直系后代
Derived from or relating to a particular line of descent; hereditary.
遗传性的：从一特定的直系后代获得的或相联系的；遗传性的
Linear.
直线的

来源：
Middle English
中古英语
from Old French
源自 古法语
from Late Latin lone3lis [consisting of lines]
源自 后期拉丁语 lone3lis [由线构成的]
from Latin lonea [line] * see line
源自 拉丁语 lonea [线] *参见 line

【引伸】
lin.eally
adv.（副词）