cor·​ner·​stone | \ ˈkȯr-nər-ˌstōn How to pronounce cornerstone (audio) \

Definition of cornerstone

1 : a stone forming a part of a corner or angle in a wall specifically : such a stone laid at a formal ceremony
2 : a basic element : foundation a cornerstone of foreign policy

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Examples of cornerstone in a Sentence

Officials held a ceremony to lay the cornerstone for a new library. Trust is the cornerstone of their relationship.
Recent Examples on the Web French President Emmanuel Macron has vowed to make climate policy a cornerstone of his administration but largely failed to uphold his own commitments after playing a large role in bargaining with 196 countries to sign on to the pact. Michael Lee, Washington Examiner, "French court finds its government guilty of violating Paris climate accord," 8 Feb. 2021 Once completed, Discovery Square 2 is expected to welcome innovative health care firms just like its glassy sister structure known as One Discovery Square, the cornerstone of the $5.6 billion Destination Medical Center (DMC) project. Janet Moore, Star Tribune, "Rochester's Destination Medical Center forges ahead, despite COVID-19," 7 Feb. 2021 As one of the last standing Freedman’s Towns in the nation, this community and its buildings are a cornerstone of African-American history in Dallas and beyond. Maggie Kelleher, Dallas News, "Tenth Street neighborhood, a treasure trove of Black history in Dallas, fights to remain intact," 5 Feb. 2021 Civilian dominance of the military, a political cornerstone of the department since its inception, was strained during the Trump administration with a commander in chief who sought to politicize its role until the very end of his term., "Senate confirms Austin in historic vote, installing first Black defense secretary," 22 Jan. 2021 Attacking trans women is, of course, the cornerstone of gender-critical feminism (of which J.K. Rowling is the most prominent practitioner)., "Biden Is Already Trying To Protect Trans Rights — & He Woke Up All The Twitter TERFs," 22 Jan. 2021 Purple is typically meant to represent bipartisanship—a clear cornerstone of the new administration after four years of divisiveness. Neha Prakash, Marie Claire, "Michelle Obama Wears Purple to Biden-Harris Inauguration," 20 Jan. 2021 Duncan Robinson appears to be different, more of a cornerstone. Ira Winderman,, "ASK IRA: Is Duncan Robinson’s free agency a Heat formality?," 28 Dec. 2020 Wheat is historically the country’s largest crop, but Syria’s self-sufficiency, a decades-old cornerstone of Baath Party’s policies, was already being undermined by war and drought. Washington Post, "Syria’s bread lines are so long that children have to skip school to wait in them," 26 Dec. 2020

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

13th century, in the meaning defined at sense 1

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Time Traveler for cornerstone

Time Traveler

The first known use of cornerstone was in the 13th century

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Last Updated

19 Feb 2021

Cite this Entry

“Cornerstone.” Dictionary, Merriam-Webster, Accessed 28 Feb. 2021.

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English Language Learners Definition of cornerstone

: a stone that forms part of a corner in the outside wall of a building and that often shows the date when the building was built
: something of basic importance

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