baseline

noun

base·​line ˈbās-ˌlīn 

often attributive

1

: a line serving as a basis

especially : one of known measure or position used (as in surveying or navigation) to calculate or locate something

2

a

: either of the lines on a baseball field that lead from home plate to first base and third base and are extended into the outfield as foul lines

b

: basepath

3

: a boundary line at either end of a court (as in tennis or basketball)

4

: a usually initial set of critical observations or data used for comparison or a control

5

: a starting point

the baseline of this discussion

Synonyms

• alpha
• beginning
• birth
• commencement
• dawn
• day one
• genesis
• get-go
• git-go
• inception
• incipience
• incipiency
• kickoff
• launch
• morning
• nascence
• nascency
• onset
• outset
• start
• threshold

Examples of baseline in a Sentence

The experiment is meant only to provide a baseline for other studies.

any year or event we use as the baseline for the Renaissance is going to be at least somewhat arbitrary

Recent Examples on the Web

But when measuring excellence, whether for individual season awards or Hall of Fame worthiness, using league average as a baseline makes more sense. —Tony Blengino, Forbes, 23 Dec. 2024

Then came a baseline cut by Matt Knowling and a find by Thomas. —Luca Evans, Orange County Register, 17 Dec. 2024

By maintaining accurate baselines between satellites, researchers can create large synthetic apertures for high-resolution imaging and astrophysical observations such as very-long-baseline interferometry for radio astronomy. —The Physics Arxiv Blog, Discover Magazine, 16 Dec. 2024

The 1850-1900 average is used as a baseline to approximate the period before the addition of greenhouse gases from burning fossil fuels such as coal, oil and gas. —Andrew Freedman, Axios, 16 Dec. 2024

Word History

First Known Use

circa 1556, in the meaning defined at sense 1

Kids Definition

baseline

noun

base·​line ˈbās-ˌlīn 

1

: a line used as a base

2

a

: either of two straight lines on a baseball field leading from home plate to first base and third base and extending into the outfield

b

: base path

Medical Definition

baseline

noun

base·​line ˈbā-ˌslīn 

: a set of critical observations or data used for comparison or a control