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

What Happens Next Gabbard warned that the growing alignment among China, Russia, Iran, and North Korea, seen since Russia's 2022 invasion of Ukraine, is unlikely to revert these bilateral relationships to a prewar 2021 baseline, even after a ceasefire is reached. —Paul Du Quenoy, MSNBC Newsweek, 26 Mar. 2025

What many people also don’t realize is that getting an accurate baseline can be as simple as getting a blood test or scheduling regular general health screenings. —Amanda Gravitis, Forbes.com, 26 Mar. 2025

Dolan has mostly stayed out of the spotlight, tending to his latest big project, The Sphere in Las Vegas, while watching games from his usual baseline seat at The Garden. —Mike Vorkunov, The Athletic, 25 Mar. 2025

Starlink’s standard home service offers 100 megabits per second download and 20 mbps upload speeds — the Federal Communications Commission’s baseline for modern internet speeds — which is typically enough to support some high-quality streaming across several devices and fast file downloads. —Bloomberg, Oc Register, 25 Mar. 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