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 of baseline

• beginning
• start
• onset
• inception
• alpha
• commencement
• launch
• 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

Beach players stepped on the baseline three times in the first half and another, trying to avoid a shot blocker, lofted a runner completely over the backboard in the second. —Mark Zeigler, San Diego Union-Tribune, 5 Nov. 2025

The tariffs start at a baseline of 10% on many nations and spike to as high as 50% on goods from India and Brazil. —Dan Mangan, CNBC, 5 Nov. 2025

Victorinox furthers its minimalist focus by using the Alox Refined treatment on three light, simple tools that provide a baseline of utility without overwhelming one's pocket. —New Atlas, 4 Nov. 2025

As a result of this framework, the company has cut direct and indirect GHG emissions (Scope 1 and Scope 2 emissions) by 84 percent from its baseline from Fiscal Year 2021. —Katherine Fung, MSNBC Newsweek, 4 Nov. 2025

Word History

First Known Use

circa 1556, in the meaning defined at sense 1

Rhymes for baseline

• acridine
• alkaline
• andesine
• anodyne
• anticline
• arginine
• asinine
• atropine
• benzidine
• borderline
• byzantine
• calamine

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