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

In critically dry years, winter-run Chinook salmon could see a 23% decrease in juvenile production compared to baseline conditions, which are already pushing the species toward extinction. —Ari Plachta, Sacramento Bee, 28 Feb. 2025

Hachimura, who has become a corner-three specialist, also is going to feast at the rim off baseline cuts against defenses that rightfully will be focused on Doncic, James and Reaves on the perimeter. —Dan Woike, Los Angeles Times, 27 Feb. 2025

At 19-9, 11-6 in the Big East, they are positioned for a first-round bye in the conference tournament and an NCAA Tournament berth, baseline achievements for the back-to-back national champs, for sure, but nothing that should be taken for granted anywhere. —Dom Amore, Hartford Courant, 27 Feb. 2025

The Crimson Tide remained well within striking distance with Henrique Pinto (24 points) finishing at the rim and Cristian Vasquez hitting a baseline pullup to even the game at 44. —Matt Feld, Boston Herald, 25 Feb. 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