Definition from Wiktionary, the free dictionary
See also: corner-stone
cornerstone (plural cornerstones)
- A stone forming the base at the corner of a building.
- Such a stone used ceremonially, often inscribed with the architect's and owner's names, dates and other details.
The cornerstone on the Flatiron Building is set on the Fifth Avenue facade.
- (figuratively) 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.
that which is prominent, fundamental, noteworthy, or central