cornerstone

noun

cor·​ner·​stone ˈkȯr-nər-ˌstōn 

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

Synonyms of cornerstone

• basis
• foundation
• bedrock

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

Bogues was selected by the Hornets in the 1988 NBA Expansion Draft and emerged as a cornerstone of the franchise. — Ryan Canfield Outkick, FOXNews.com, 27 Oct. 2026

Bolsonaro made a tough-on-crime approach the cornerstone of his campaign and pledged to bring down food costs while Lula, trying to lure undecided voters, has invested in costly incentives. — Arkansas Online, 26 Oct. 2026

Tyler Herro, a Milwaukee-area native who was one of four players shipped to the Bucks in a blockbuster off-season trade that sent franchise cornerstone Giannis Antetokounmpo to the Miami Heat, had 34 points. — ABC News, 23 Oct. 2026

Each became a cornerstone of Eighties country music, but Anderson didn’t stop there. — Joseph Hudak, Rolling Stone, 22 Oct. 2026

Word History

First Known Use

13th century, in the meaning defined at sense 1

Rhymes for cornerstone

• acetone
• anglophone
• baritone
• bourguignon
• buspirone
• chaperon
• chaperone
• cobblestone
• collarbone
• cortisone
• dictaphone
• dithizone

Kids Definition

cornerstone

noun

cor·​ner·​stone ˈkȯr-nər-ˌstōn 

1

: a stone forming part of a corner in a wall

2

: something of basic importance

the cornerstone of our foreign policy