noun, often attributive
base·​line | \ ˈbās-ˌlīn How to pronounce baseline (audio) \

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
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 Gardner’s 3 came after Tulane freshman Sion James sank his first career 3-pointer from the baseline off a pass from R.J. McGee with 1:11 left, giving the Wave a 54-50 cushion after the Pirates had scored five in a row. G Smith,, "Tulane holds Jayden Gardner to career low, avenges loss to ECU with stifling defense," 2 Jan. 2021 Counties in Southern California were also starting from a higher baseline, and many never reached the very low levels that Bay Area counties saw in October. Kellie Hwang,, "These charts compare the COVID surge in Southern California vs. the Bay Area," 31 Dec. 2020 With his team needing to go the length of the court in 3.9 seconds, Utes guard Pelle Larsson took the inbounds pass from the baseline. Ben Bolch, Los Angeles Times, "UCLA overcomes gaffes and a Chris Smith injury scare to beat Utah," 31 Dec. 2020 That was the baseline for President Bill Clinton, who entered the White House in 1993. Camille Caldera, USA TODAY, "Fact check: Clinton, Obama left federal government with a lower deficit than when they arrived," 1 Jan. 2021 Masks were the baseline, and other more extreme trends started to appear. Liana Satenstein, Vogue, "Naomi Campbell’s Hazmat Suit Was One of the Most Symbolic Looks of 2020," 29 Dec. 2020 Hogan sets statewide policies that are the baseline for all of Maryland, but local leaders have authority to be more strict if necessary. Washington Post, "Maryland’s coronavirus numbers are going up. Here’s what you need to know.," 20 Nov. 2020 One in which civility, respect and integrity are a baseline. Editorial Board Star Tribune, Star Tribune, "Biden's unifying message, optimism won the presidency," 7 Nov. 2020 The health baseline most doctors use is body mass index, or BMI, a score based on height and weight. Washington Post, "Amazon’s new health band is the most invasive tech we’ve ever tested," 10 Dec. 2020

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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Time Traveler for baseline

Time Traveler

The first known use of baseline was circa 1556

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Statistics for baseline

Last Updated

19 Jan 2021

Cite this Entry

“Baseline.” Dictionary, Merriam-Webster, Accessed 25 Jan. 2021.

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More Definitions for baseline


How to pronounce baseline (audio)

English Language Learners Definition of baseline

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


base·​line | \ ˈbā-ˌslīn How to pronounce baseline (audio) \

Medical Definition of baseline

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

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