longitudinal

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Of or relating to longitude or length.
• adjective Concerned with the development of persons or groups over time.
• adjective Placed or running lengthwise.

from The Century Dictionary.

• Of or pertaining to longitude or length; relating to or consisting in length: as, longitudinal distance.
• In the direction of the length; running lengthwise, as distinguished from transverse or across: as, the longitudinal diameter of a body.
• In botany, in the direction of growth.
• In zoology, extended in the long axis of the body, as any articulate animal; articulated.
• noun In iron ship-building, one of the fore-and-aft members in the framing of a cellular double bottom, consisting of a plate, an inner angle-bar by which it is connected to the inner bottom, and an outer angle-bar by which it is connected to the outside plating. In warships, the plate and inner bar are usually continuous; in merchant vessels the plate and both bars are more frequently worked inter-costally between the frames. Also called longitudinal frame. See cuts under double bottom.

from the GNU version of the Collaborative International Dictionary of English.

• noun A railway sleeper lying parallel with the rail.
• adjective Of or pertaining to longitude or length.
• adjective Extending in length; in the direction of the length; running lengthwise, as distinguished from transverse.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective Relating to length, or to longitude.
• adjective Running in the direction of the long axis of a body.
• adjective Forward and/or backward, relative to some defined direction.
• adjective of a study Sampling data over time rather than merely once.
• noun Any longitudinal piece, as in shipbuilding etc.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• adjective of or relating to lines of longitude
• adjective running lengthwise
• adjective over an extended time