longitudinal adj 1: of or relating to lines of longitude; "longitudinal reckoning by the navigator" 2: running lengthwise; "a thin longitudinal strip"; "longitudinal measurements of the hull" 3: over an extended time; "a longitudinal study of twins"
Longitudinal \Lon`gi*tu"di*nal\, a. [Cf. F. longitudinal.] 1. Of or pertaining to longitude or length; as, longitudinal distance. [1913 Webster] 2. Extending in length; in the direction of the length; running lengthwise, as distinguished from {transverse}; as, the longitudinal diameter of a body. --Cheyne. [1913 Webster]
Longitudinal \Lon`gi*tu"di*nal\, n. A railway sleeper lying parallel with the rail. [1913 Webster]