- The definition of a cornerstone is a stone at the corner of a building, or a basic, essential part of something.
- An example of a cornerstone is the first piece of stone placed for a new building, often inscribed with the date to commemorate the occasion.
- An example of a cornerstone is the belief by Christians in Christ as the Son of God.
- a stone that forms part of the corner of a building; esp., a foundation stone of this kind, often inscribed, laid at a ceremony that marks the beginning of building
- the basic, essential, or most important part; foundation
Origin of cornerstoneMiddle English
also corner stone
- a. A stone at the corner of a building uniting two intersecting walls; a quoin.b. Such a stone, often inscribed, laid at a ceremony marking the origin of a building.
- An indispensable and fundamental basis: the cornerstone of an argument.
- A ceremonial stone set at the corner of a building, joining two exterior walls, and often inscribed with the starting and completion dates of construction, the name of the architect and owner, and other details.
- The cornerstone on the Flatiron Building is set on the Fifth Avenue facade.
- By extension, that which is prominent, fundamental, noteworthy, or central.
- Exceptional service is the cornerstone of the hospitality industry.
- That is the cornerstone of any meaningful debate about budgets and projects, regulations and policies.