baseline

American  

[beys-lahyn] / ˈbeɪsˌlaɪn /

noun

1. Baseball. the area between bases base bases basis within which a base runner must keep when running from one base bases 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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Etymology

Origin of baseline

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

Example Sentences

Sinha's interest in the fasting mimicking diet came from earlier research showing it could lower levels of C-reactive protein, a marker of inflammation, in people with elevated baseline levels.

From Science Daily • Apr. 3, 2026

Beyond these concerns, there is a more fundamental problem: India has been making policy without a recent population baseline.

From BBC • Mar. 31, 2026

January’s home price data offers a baseline before recent mortgage rate hikes, reflecting a period of optimism and lower rates.

From Barron's • Mar. 30, 2026

It was Dodger Stadium on Wednesday, when the grass outside the baseline and the bright red sign high above center field read “UNIQLO FIELD.”

From Los Angeles Times • Mar. 26, 2026

Jackie Harris took his place on one side of the court, and a large Wallace player lined up on the opposite baseline.

From "The Parker Inheritance" by Varian Johnson

Related Words

• control
• criterion
• guideline
• measure
• standard