cornerstone
Americannoun
-
a stone uniting two masonry walls at an intersection.
-
a stone representing the nominal starting place in the construction of a monumental building, usually carved with the date and laid with appropriate ceremonies.
-
something that is essential, indispensable, or basic.
The cornerstone of democratic government is a free press.
-
the chief foundation on which something is constructed or developed.
The cornerstone of his argument was that all people are created equal.
noun
-
a stone at the corner of a wall, uniting two intersecting walls; quoin
-
a stone placed at the corner of a building during a ceremony to mark the start of construction
-
a person or thing of prime importance; basis
the cornerstone of the whole argument
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.
Vocabulary lists containing cornerstone
Determined to Stay
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
The Secret Hum of a Daisy
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
George's Cosmic Treasure Hunt
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Many Jamaicans are fiercely proud of the island's Scotch bonnets, which are something of a cultural cornerstone and a central feature in its cuisine.
From BBC • May 31, 2026
“These investments are the cornerstone of a resilient and thriving platform ecosystem, and we are prepared to invest over the long term.”
From The Wall Street Journal • May 27, 2026
Leo has made the hot-button issue a cornerstone of his papacy in dedicating to it his first encyclical -- a document which lays the basis for Church teaching and longer-term debate.
From Barron's • May 25, 2026
Brink would be a cornerstone player for almost any team in the league, yet she’s coming off the bench with high expectations for her to be one of the team’s most important players.
From Los Angeles Times • May 23, 2026
The Youth League drafted a Program of Action, the cornerstone of which was a campaign of mass mobilization.
From "Long Walk to Freedom" by Nelson Mandela
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
