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

The Federal Open Market Committee (FOMC), the panel of Fed officials responsible for setting interest rates, is expected to keep its baseline interest rate unchanged Wednesday. —Sylvan Lane, The Hill, 18 June 2025

The trade framework signed Monday with the United Kingdom included quotas to protect against some tariffs, but the 10% baseline would largely remain as the Trump administration is banking on tariff revenues to help cover the cost of its income tax cuts. —Josh Boak, Chicago Tribune, 17 June 2025

The trade framework included quotas to protect against some tariffs, but the 10% baseline would largely remain as the Trump administration is banking on tariff revenues to help cover the cost of its income tax cuts. —Rob Gillies, Fortune, 17 June 2025

The president imposed tariff rates of 10% and up on imports from nearly all countries, which upended global markets and sparked fears of a recession, prompting Trump to later issue a 90-day pause on the worst of his tariffs and only keep a 10% baseline rate in place. —Alison Durkee, Forbes.com, 17 June 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