cornerstone

[kawr-ner-stohn]

noun

1. a stone uniting two masonry walls at an intersection.

2. a stone representing the nominal starting place in the construction of a monumental building, usually carved with the date and laid with appropriate ceremonies.

3. something that is essential, indispensable, or basic.

   The cornerstone of democratic government is a free press.

4. the chief foundation on which something is constructed or developed.

   The cornerstone of his argument was that all people are created equal.

cornerstone

/ ˈkɔːnəˌstəʊn /

noun

1. a stone at the corner of a wall, uniting two intersecting walls; quoin

2. a stone placed at the corner of a building during a ceremony to mark the start of construction

3. a person or thing of prime importance; basis

   the cornerstone of the whole argument

Word History and Origins

Origin of cornerstone¹

Middle English word dating back to 1250–1300; corner, stone

Example Sentences

More than a century after its opening, the canal remains an unparalleled triumph of infrastructure and a cornerstone of our globalized economy, in which 80% of trade moves by sea.

Read more on The Wall Street Journal

Lecornu’s benighted tenure—the shortest in the history of France’s modern Fifth Republic—is a measure of how a political system that was once a cornerstone of stability in Europe has fallen into disarray.

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The 1998 Belfast Agreement, the cornerstone of peace in Northern Ireland, and the post-Brexit deal with the European Union placed respect for human rights law at their centre.

Read more on BBC

Academic research is a cornerstone of U.S. pharmaceutical R&D: A 2020 study found that “NIH funding contributed to research associated with every new drug approved from 2010-2019, totaling $230 billion.”

Read more on Los Angeles Times

These include new work requirements that are a cornerstone of Republican demands, under which certain adults would have to work or engage in qualifying activities to maintain Medicaid benefits.

Read more on Salon

Related Words

• essential 
• foundation 
• keystone 
• linchpin 
• mainstay 
• pillar