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.

---

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

---

Etymology

Origin of baseline

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

Example Sentences

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

In all, the firm has raised baseline 2026 gross domestic product growth forecasts for Asia-Pacific—excluding China—to 4.5% from 4.2%.

From The Wall Street Journal • Mar. 25, 2026

They compared outcomes between those who also used hormone therapy and those who did not, ensuring both groups had similar baseline characteristics.

From Science Daily • Mar. 23, 2026

Sometimes such radio telescopes are connected with telescopes on the other side of the Earth, forming a baseline comparable to the Earth’s diameter—in a certain sense, a telescope as large as the planet.

From "Cosmos" by Carl Sagan

Related Words

• control
• criterion
• guideline
• measure
• standard