cornerstone

American  

[kawr-ner-stohn] / ˈkɔr nərˌstoʊn /

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.

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cornerstone British  

/ 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

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Etymology

Origin of cornerstone

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

Example Sentences

The complex run by the Saudi state oil giant Aramco is home to one of the largest refineries in the entire Middle East and a cornerstone of the kingdom's energy sector.

From Barron's

Located on Saudi Arabia’s Persian Gulf coast, the Ras Tanura complex is a cornerstone of the kingdom’s energy sector.

From The Wall Street Journal

Carney has made boosting commerce with Europe and Asia cornerstones of his strategy to backstop Canada's economy, should free trade with Washington collapse.

From Barron's

The Museum of Contemporary Art has acquired Kara Walker’s sculpture “Unmanned Drone,” a cornerstone of the museum’s groundbreaking “Monuments” exhibition.

From Los Angeles Times

The Hubble Space Telescope has now operated for more than 30 years and remains a cornerstone of astronomical discovery.

From Science Daily

Related Words

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