Cornerstone
WordNet
noun
(1) A stone at the outer corner of two intersecting masonry walls
(2) A stone in the exterior of a large and important building; usually carved with a date and laid with appropriate ceremonies
(3) The fundamental assumptions from which something is begun or developed or calculated or explained
"The whole argument rested on a basis of conjecture"
WiktionaryText
Noun
- 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.