cornerstone

American  

[kawr-ner-stohn] / ˈkɔr nərˌstoʊn /

noun

• cornerstones
  plural

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 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

---

Other Word Forms

Noun Inflected Forms

• cornerstones
  plural

---

Etymology

Origin of cornerstone

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

---

Explanation

A cornerstone is literally a stone at the corner of a building. It’s an important stone, so it also means “the basic part of something,” as in, the cornerstone of the suffragette movement was getting women the right to vote. When a building goes up, putting in the cornerstone is a big deal and people celebrate. Many cornerstones are engraved with historical information about the building, such as the year the building was built. The cornerstone is sometimes made of a different material from the rest of the building too. From the sense of "foundation," cornerstone also means "essential element.” If you’re really into Italian food, you might say that pasta is the cornerstone of your diet.

Example Sentences

See Examples For:

cornerstone cornerstones

“Ride safety is a cornerstone of our business, and when we see guest confidence affected, we take it seriously.”

From Los Angeles Times ● Oct. 13, 2026

"I want my kids to say, 'Mom worked really hard for something very important,' because it is very important. It's the cornerstone of our country," she said.

From Barron's ● Oct. 5, 2026

Meanwhile, the annual checkup, long the cornerstone of preventive care, is faltering.

From MarketWatch ● Oct. 5, 2026

It said in September that it had secured commitments from more than 20 cornerstone investors, including BlackRock and T. Rowe Price.

From The Wall Street Journal ● Oct. 2, 2026

“Emotion is the cornerstone of humanity, my child. It’s not something that can be avoided. Even my power is drawn from raw emotion. You’ve seen that, haven’t you?”

From "Kwame Crashes the Underworld" by Craig Kofi Farmer

As tech has grown as an overwhelming force in our lives, the visual design cornerstones associated with it—arial font, minimalist branding, bright colors and clean lines—have become the norm.

From Slate ● Aug. 21, 2026

This devotion to authenticity is one of Thompson’s cornerstones.

From Salon ● May 15, 2026

Homeownership is one of the cornerstones of the American dream, deeply ingrained in our culture as a symbol of financial success and stability.

From MarketWatch ● Apr. 24, 2026

"Section 33 constitutes, in a way, one of the cornerstones of the Canadian Charter," Quebec argues in legal briefings.

From BBC ● Mar. 22, 2026

Though the Barnetts, Abbott, Jackson, and Hill are long gone, the Defender, the Urban League, the NAACP, and Quinn Chapel remain cornerstones of the community, still called home by both middle class and poor.

From "A Few Red Drops: The Chicago Race Riot of 1919" by Claire Hartfield

Random Word

Spin the wheel and learn a new word!

---

Related Words

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

---