\Lon`gi*tu"di*nal\, a. [Cf. F. longitudinal.] 1. Of or pertaining to longitude or length; as, longitudinal distance. 2. Extending in length; in the direction of the length; running lengthwise, as distinguished from transverse; as, the longitudinal diameter of a body. --Cheyne.
\Lon`gi*tu"di*nal\, n. A railway sleeper lying parallel with the rail.