baseline

American  

[beys-lahyn] / ˈbeɪsˌlaɪn /

noun

• baselines
  plural

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. Surveying. triangulation1

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 Architecture. a line on the body plan or sheer plan of a hull, representing a horizontal reference plane for vertical dimensions.

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adjective

1. basic or essential.

baseline British  

/ ˈbeɪsˌlaɪn /

noun

1. surveying a measured line through a survey area from which triangulations are made

2. an imaginary line, standard of value, etc, by which things are measured or compared

3. a line at each end of a tennis court that marks the limit of play

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Other Word Forms

Noun Inflected Forms

• baselines
  plural

Etymology

Origin of baseline

First recorded in 1740–50; base ¹ + line ¹

Explanation

A baseline is an imaginary starting point or basis of comparison for something. To test how a class's performance improves over time, a researcher might begin with a baseline showing their current scores and grades. You're most likely to encounter baseline in technical or work-related writing, since it's mainly used to talk about comparing data. In land surveying, the baseline runs east and west, and all measurements and surveys are based on that main line. There's also a baseline in sports, marking certain boundaries on the field or court, including the route a baseball player takes rounding the bases toward home plate.

Example Sentences

See Examples For:

baseline baselines

Enter Reinsve and Stan, an ideal pair of leads capable of providing the understated, baseline emotion that Mungiu requires to pull off an undertaking as tricky as “Fjord.”

From Salon ● Sep. 19, 2026

Baker-Mazara, who dealt with nagging injuries all season that held him out of practice, spent the remainder of the game in a folding chair on the baseline, away from the rest of the team.

From Los Angeles Times ● Sep. 15, 2026

As he stepped up to the baseline, Alexander Zverev could be forgiven for letting his mind slip back to the last time he served for the US Open title.

From BBC ● Sep. 14, 2026

After 10 years, the debt would be 109% of GDP instead of the baseline of 120%—but it would still be climbing.

From The Wall Street Journal ● Sep. 13, 2026

Ben dribbled toward the center of the court, spotted Philip backdooring his man near the baseline and shuffled a pass beneath Rostelli’s arms.

From "The Great Santini" by Pat Conroy

Earlier this month, key members of the OPEC+ alliance agreed to keep output stable in October after six straight monthly increases, as they review members’ production capacity baselines to determine future quotas.

From The Wall Street Journal ● Sep. 10, 2026

Though grocery costs may decrease slightly once fuel costs stabilize, they are unlikely to return to prewar baselines as retailers adjust to higher prices, Vyas noted, pointing to sustained increases in food costs post-pandemic.

From Los Angeles Times ● Sep. 4, 2026

"Iraq's request may become part of the 2027 capacity review, where production baselines will be examined," he added.

From Barron's ● Jul. 5, 2026

With shorter points, lower-bouncing balls and the risk of slippy baselines, the Wimbledon grass is not easy to master for those who have not grown up playing on it.

From BBC ● Jun. 28, 2026

A. Ground strokes=All shots hit from the baselines off the bounce of the ball.

From The Art of Lawn Tennis by William (Bill) Tatem Tilden

Related Words

• control
• criterion
• guideline
• measure
• standard