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

Coordination and communication, after all, are cornerstones of any music scene. —Evan Minsker, Rolling Stone, 7 Feb. 2026

Local business growth Our vibrant local business community is a cornerstone of Bee Cave’s success. —Kara King, Austin American Statesman, 6 Feb. 2026

The Cavaliers traded Sexton to the Utah Jazz in 2022 as a cornerstone of the trade that brought Donovan Mitchell to Cleveland. —Julia Poe, Chicago Tribune, 6 Feb. 2026

Lynch believes the Legion of Boom defense combined with himself, Wilson and a host of cornerstone receivers could have gone on to win at least one more Super Bowl if not more. —Kyle Feldscher, CNN Money, 6 Feb. 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