adjective

• Having an ancestral relationship to mothers, fathers, grandparents, (etc.) and having a descendant relationship to sons, daughters, grandchildren (etc.), exclusive of collateral siblings.
• Inheriting by direct descent; having the right by direct descent to succeed (to).
• Composed of lines; delineated.
• In the direction of a line; of a line; of or relating to a line; measured on, or ascertained by, a line; linear.