noun Also base line.
- Baseball. the area between bases within which a base runner must keep when running from one base to another.
- Tennis. the line at each end of a tennis court, parallel to the net, that marks the in-bounds limit of play.
- (in perspective drawing) a horizontal line in the immediate foreground formed by the intersection of the ground plane and the picture plane.
- a basic standard or level; guideline: to establish a baseline for future studies.
- a specific value or values that can serve as a comparison or control.
- Typography. the imaginary line on which the bottoms of primary letters align.
- Surveying. See under triangulation(def 1).
- Electronics. a horizontal or vertical line formed on the face of a cathode-ray tube by the sweep of the scanning dot.
- Naval Architecture. a line on the body plan or sheer plan of a hull, representing a horizontal reference plane for vertical dimensions.
- basic or essential.
- surveying a measured line through a survey area from which triangulations are made
- an imaginary line, standard of value, etc, by which things are measured or compared
- a line at each end of a tennis court that marks the limit of play