/ Dictionary / Index B baseline: Meaning and Definition of Find definitions for: base•line Pronunciation: (bās'līn"), [key] — n. the area between bases within which a base runner must keep when running from one base to another. 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. the imaginary line on which the bottoms of primary letters align. See under(def. 1). a horizontal or vertical line formed on the face of a cathode-ray tube by the sweep of the scanning dot. a line on the body plan or sheer plan of a hull, representing a horizontal reference plane for vertical dimensions. —adj. basic or essential. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: baseline (Thesaurus) base level baseliner Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language