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

Empathy is a cornerstone of effective leadership, yet narcissistic leaders often dismiss the needs or emotions of others. —Cheryl Robinson, Forbes, 16 Jan. 2025

Sousa Design’s holistic model is the cornerstone of its success. —Chris Gallagher, USA TODAY, 16 Jan. 2025

Malkin is a cornerstone of the Pittsburgh Penguins, having spent his entire 18-year career with the team. —Michael Gfoeller and David H. Rundell, Newsweek, 15 Jan. 2025

The annual two weekend-long event is a cornerstone of the city's festival season, not to mention a massive shot in the arm to the city's hospitality industry, too. —Chelsea Brasted, Axios, 15 Jan. 2025

Word History

First Known Use

13th century, in the meaning defined at sense 1

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