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

• base
• basis
• bedrock
• bottom
• footing
• foundation
• ground
• groundwork
• keystone
• root
• underpinning
• warp
• warp and woof

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

Gregg Popovich, who has won more games than any coach in NBA history and transformed the San Antonio Spurs into one of the league’s cornerstone franchises of the 21st century, is stepping down as head coach and will become the team’s president of basketball operations. —Joe Vardon, New York Times, 2 May 2025

The multi-year project is expected to generate thousands of highly skilled jobs while cementing Mumbai’s position as a cornerstone of global film production. —Naman Ramachandran, Variety, 2 May 2025

Each of these programs is a cornerstone of CMA’s commitment to honoring the people and moments that propel Country Music to new heights. —Paul Grein, Billboard, 1 May 2025

Medical imaging has long been a cornerstone of diagnosis. —Vinodhini Ravikumar, Forbes.com, 29 Apr. 2025

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