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

Its impending end has rung alarm bells across social media, with a baseline tariff as high as 145% depending on the carrier set to take effect on Chinese imports, potentially more than doubling the cost for all those cheap products deal-hungry Americans scooped up. —Elisabeth Buchwald, CNN Money, 2 May 2025

But it also may be pushed closer to a year and a half which is more or less the new baseline for series like this. —Paul Tassi, Forbes.com, 30 Apr. 2025

Days later, as investors appeared spooked, Mr. Trump announced a 90-day pause on most of his new tariffs, keeping the 10% baseline in place while raising the tariff rate on goods imported from China. —Kaia Hubbard, CBS News, 30 Apr. 2025

The statement echoes many of the complaints the tariffs’ detractors have shouted since April 2, when the president first imposed country-specific reciprocal tariffs on dozens of countries, before pushing those duties back 90 days to make room for 10-percent baseline duties. —Glenn Taylor, Sourcing Journal, 29 Apr. 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