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

Public safety is a cornerstone of our society, and Texans must be able to rely on law enforcement to do their jobs to keep Texas families and communities safe. —Eleanor Dearman, Fort Worth Star-Telegram, 14 Feb. 2026

Trump has made aggressive immigration enforcement a cornerstone of his second term in office, while Democrats appear emboldened by new polling showing broad support for new restrictions on ICE. —Nik Popli, Time, 13 Feb. 2026

Science pointing the way to the next renaissance The cornerstone of this new era, according to Hassabis, is the application of AI to biology. —Nick Lichtenberg, Fortune, 11 Feb. 2026

Newcomers help spur on Charlotte job growth The cornerstone of this expansion is a steady influx of new residents. —Charlotte Observer, 11 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