key·​stone | \ ˈkē-ˌstōn How to pronounce keystone (audio) \

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

Examples of keystone in a Sentence

Tourism is the city's economic keystone. the keystone of his faith
Recent Examples on the Web His greatest victory to date was in Shelby County v. Holder in 2013, where the Supreme Court shattered a keystone provision of the Voting Rights Act of 1965. Matt Ford, The New Republic, 28 Dec. 2021 Bergman Island, especially, serves as a keystone for understanding 2021's Bergmanaissance. Jeva Lange, The Week, 22 Sep. 2021 Imagine all the lives saved or injuries averted by having used a horn as a keystone to achieving safety. Lance Eliot, Forbes, 1 Sep. 2021 And the story of one — along with other suggestions for kindnesses throughout the year — is told over the months of their 2022 Kindness Calendar, the keystone to their fundraising. Washington Post, 23 Dec. 2021 Clues here include four Ionic columns supporting the portico, multipaned windows and lintels decorated with acanthus leaves, rather than the keystone lintels of the Federal period. Washington Post, 5 Nov. 2021 For Asheville’s Southside, where 58% of Black families owned their homes, Urban Renewal created mass displacement, fractured physical and spiritual community, and dislodged the keystone of generational wealth building. Adam Erace, Fortune, 7 Nov. 2021 This projector features a native resolution of 1080p, Bluetooth 5 connectivity, and a 4-point keystone correction function for varied viewing angles. Forbes Vetted, Forbes, 21 June 2021 With a crystal clear Full HD picture, a great brightness rating of 9500 lumens, and cutting-edge features such as automatic 6D keystone correction, this model should definitely retail for more than $600. Maren Estrada, BGR, 16 June 2021

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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Time Traveler for keystone

Time Traveler

The first known use of keystone was circa 1637

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Dictionary Entries Near keystone

key station


keystone effect

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Last Updated

13 Jan 2022

Cite this Entry

“Keystone.” Dictionary, Merriam-Webster, Accessed 18 Jan. 2022.

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More Definitions for keystone



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


key·​stone | \ ˈkē-ˌstōn How to pronounce keystone (audio) \

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

More from Merriam-Webster on keystone

Nglish: Translation of keystone for Spanish Speakers Encyclopedia article about keystone


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