noun, often attributive
base·line | \ˈbās-ˌlīn \

Definition of baseline 

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

2a : 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

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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 two younger Mary Pages set the baseline beautifully. Jesse Green, New York Times, "Review: ‘Mary Page Marlowe’ Lives an Ordinary, Extraordinary Life," 12 July 2018 There is no sign that Kim Jong Un is contemplating what nuclear experts say has to be the first step: a full disclosure of his weapons program, to create a baseline for future inspection and verification, fundamental to any arms-control agreement. NBC News, "North Korea shatters Trump's boastful assurances of an easy path to denuclearization," 7 July 2018 In the same way, there’s a chance the California standard will become the baseline for Internet privacy when the law takes effect on Jan. 1, 2020. Hiawatha Bray,, "Calif.’s Net privacy law gives consumers more clout, and Big Tech may be just fine with that," 1 July 2018 And to create a baseline for the other two categories, a panel of moms had to unanimously agree on whether the cry was either hungry or fussy. CBS News, "ChatterBaby app could help parents figure out why their baby is crying," 28 June 2018 This year's data will set a baseline for years to come, with the goal being to improve the outcomes. Lori Higgins, Detroit Free Press, "This may explain why Detroit schools struggle to recruit students, staff," 13 June 2018 With runners on first and third, Singer fielded a bunt by Someillian and tagged out Guardascione sprinting down the third baseline for JU’s second out. Edgar Thompson,, "Gators' P Brady Singer returns, leads UF to 3-2 win over JU in NCAAs," 3 June 2018 But injury and some spotty scouting tape, coupled with arm length and weight measurements considered below the baseline for an NFL-level tackle, caused evaluators to reconsider how and where Williams might fit in the NFL. Nick Moyle, Houston Chronicle, "Cowboys draft Texas OL Connor Williams," 27 Apr. 2018 The ruling was reversed after the umpires met and said Benintendi was out of the baseline, deleting his hit. Dave Clark,, "Madeira's Andrew Benintendi falls short in All-Star Final Vote," 11 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'baseline.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of baseline

circa 1556, in the meaning defined at sense 1

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Statistics for baseline

Last Updated

4 Oct 2018

Look-up Popularity

Time Traveler for baseline

The first known use of baseline was circa 1556

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More Definitions for baseline



English Language Learners Definition of baseline

: information that is used as a starting point by which to compare other information

: a line at either end of the playing area in games like basketball and tennis

baseball : either one of the lines that lead from home plate to first base and third base


base·line | \ˈbā-ˌslīn \

Medical Definition of baseline 

: a set of critical observations or data used for comparison or a control

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Comments on baseline

What made you want to look up baseline? Please tell us where you read or heard it (including the quote, if possible).


one that holds something together

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