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
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

It hasn’t been seen often from Roger Federer in recent years, but the 20-time Grand Slam champion has been known to sprinkle in a few dribbles along the baseline before serves. Marc Stein, New York Times, "For These Tennis Pros, (Basket)ball Is Life," 28 Aug. 2019 The right kind of diversity training can be valuable for establishing a baseline of knowledge, setting expectations, and enabling everyone to become more self-aware. Michelle Murphy, Quartz at Work, "Truly effective diversity training can be measured in goosebumps," 24 July 2019 Chief among the law's focus are clear targets, set using a baseline of 1990 emissions. John Timmer, Ars Technica, "New York passes its Green New Deal, announces massive offshore wind push," 19 July 2019 That September, though, a fan was struck by a bat that cleared the netting along the baseline. Jordan Frias,, "Foul ball injures fan at Fenway Park on Saturday night," 14 July 2019 The Fever tried to create a look for Kelsey Mitchell for the tying 3-pointer, but the Aces swarmed her along the left baseline, forcing her to take a long two that missed the mark. Akeem Glaspie, Indianapolis Star, "Fever falter down the stretch, lose close game to Aces," 10 July 2019 Yes, LeBron James’ entrance to take his first-row seat along the baseline Friday night at the NBA’s summer league caused quite the stir. K.c. Johnson,, "4 takeaways from the Bulls’ summer league opener, including Daniel Gafford’s energy and Shaq Harrison’s defense," 6 July 2019 Goffin was able to hang in there at the baseline and his on-the-run passing shots were dialed in. Howard Fendrich, Houston Chronicle, "Novak Djokovic's 10-game run tops David Goffin in Wimbledon quarterfinal," 10 July 2019 Thiem, looking lower on energy and inspiration, could not hold his own, and Nadal soon ran out the match, mixing successful forays to the net with his customary precision and court coverage at the baseline. Christopher Clarey, New York Times, "Rafael Nadal, Pillar of Roland Garros, Wins the French Open for the 12th Time," 9 June 2019

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

20 Sep 2019

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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

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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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).


formidable, illustrious, or eminent

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