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

All of that came just a few years after the university shuttered its law school, and as the university was mired in a national controversy over the sale of cornerstone artwork from its campus museum to fund dorm renovations for first-year students. — Amy Lavalley, Chicago Tribune, 26 July 2026

Boston’s about to find out what its franchise cornerstone is made of. — Kristian Winfield, New York Daily News, 25 July 2026

As Napa’s appeal expands from the vineyards to downtown, The Charles looks to become a cornerstone of the LGBTQ+ community in the area. — Matt Kirouac, Travel + Leisure, 25 July 2026

However, funding for surveillance and response capacity remains widely recognized as a cornerstone for effective outbreak control. — Omer Awan, Forbes.com, 24 July 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