Pronunciation: (bās'līn"), [key]
—n. Also,base' line".
1. Baseball.the area between bases within which a base runner must keep when running from one base to another.
2. Tennis.the line at each end of a tennis court, parallel to the net, that marks the in-bounds limit of play.
3. (in perspective drawing) a horizontal line in the immediate foreground formed by the intersection of the ground plane and the picture plane.
4. a basic standard or level; guideline: to establish a baseline for future studies.
5. a specific value or values that can serve as a comparison or control.
6. Typography.the imaginary line on which the bottoms of primary letters align.
7. Survey.See under triangulation (def. 1).
8. Electronics.a horizontal or vertical line formed on the face of a cathode-ray tube by the sweep of the scanning dot.
9. Naval Archit.a line on the body plan or sheer plan of a hull, representing a horizontal reference plane for vertical dimensions.
basic or essential.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.