Lineal

Lin"e*al (lĭn"ē*al), a. [L. linealis belonging to a line, fr. linea line: cf. F. linéal. See 3d Line.] 1. Descending in a direct line from an ancestor; hereditary; derived from ancestors; -- opposed to collateral; as, a lineal descent or a lineal descendant.

The prime and ancient right of lineal succession.
Locke.

2. Inheriting by direct descent; having the right by direct descent to succeed (to).

For only you are lineal to the throne.
Dryden.

3. Composed of lines; delineated; as, lineal designs.

4. In the direction of a line; of or pertaining to a line; measured on, or ascertained by, a line; linear; as, lineal magnitude.

Lineal measure, the measure of length; -- usually written linear measure.