keystone

noun
key·stone | \ ˈkē-ˌstōn \

Definition of keystone 

1 : the wedge-shaped piece at the crown of an arch that locks the other pieces in place — see arch illustration

2 : something on which associated things depend for support determination, a keystone of the puritan ethic —L. S. Lewis

3 or keystone species : a species of plant or animal that produces a major impact (as by predation) on its ecosystem and is considered essential to maintaining optimum ecosystem function or structure

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Examples of keystone in a Sentence

Tourism is the city's economic keystone. the keystone of his faith

Recent Examples on the Web

The North Atlantic Treaty Organization, which has been a keystone of global security since its formation in 1949, does not involve a membership that collects dues. W.j. Hennigan, Time, "President Trump Says NATO Allies Owe the U.S. Money. He's Wrong," 11 July 2018 Dodd-Frank was the keystone of Obama’s post-2008 recession measures to prevent another meltdown. BostonGlobe.com, "Trump’s trophy case," 15 June 2018 Get ready for a seismic summer, with James and Paul George hitting free agency, plus several other keystones inching closer to the trade market. Lee Jenkins, SI.com, "Kevin Durant and the Dagger That Foreshadowed the Broom," 12 June 2018 Remember: Pennsylvania, the keystone of the president’s 2016 victory, will be a battleground in 2018 and 2020. James Hohmann, Washington Post, "The Daily 202: RFK’s speech in apartheid South Africa remains relevant 50 years after his assassination," 5 June 2018 Essential clinical services, such as providing medication to address cravings for opioids, instituting behavioral health counseling, and recommending support groups, are the keystones for successful recovery. Jay Chaudhary, STAT, "Opioid recovery teams benefit from the addition of lawyers," 29 May 2018 Trump has made protecting American manufacturing workers — and the iconic auto industry, in particular — a keystone of his administration. Bloomberg, latimes.com, "Trump threat of auto tariffs provokes sharp responses from U.S. trade partners," 24 May 2018 Indeed, Boldin grasps that while far-flung explorations at the margins of the repertoire bring their own rewards, those pleasures also sit just fine alongside the visceral thrills offered by the great keystone works of the chamber music literature. Jeremy Eichler, BostonGlobe.com, "Passing the two-decade mark, Chameleon forges ahead with music looking back," 22 May 2018 If Democrats are going to retake the House, Pennsylvania will be the keystone. James Hohmann, Washington Post, "The Daily 202: The far left is winning the Democratic civil war," 16 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'keystone.' 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 keystone

circa 1637, in the meaning defined at sense 1

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Statistics for keystone

Last Updated

9 Aug 2018

Look-up Popularity

Time Traveler for keystone

The first known use of keystone was circa 1637

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More Definitions for keystone

keystone

noun

English Language Learners Definition of keystone

: a large stone at the top of an arch that locks the other stones in place

: something on which other things depend for support

keystone

noun
key·stone | \ ˈkē-ˌstōn \

Kids Definition of keystone

1 : the wedge-shaped piece at the top of an arch that locks the other pieces in place

2 : something on which other things depend for support

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Comments on keystone

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