Cornerstone

noun

noun ·3 syllables ·Moderate ·College level

Definitions

Noun
  1. 1
    A stone forming the base at the corner of a building.

    "Clutch it like a cornerstone Otherwise it all comes down Justify denials and Grip 'em to the lonesome end"

  2. 2
    a stone at the outer corner of two intersecting masonry walls wordnet
  3. 3
    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."

  4. 4
    a stone in the exterior of a large and important building; usually carved with a date and laid with appropriate ceremonies wordnet
  5. 5
    That which is prominent, fundamental, noteworthy, or central. figuratively

    "Exceptional service is the cornerstone of the hospitality industry."

Show 1 more definition
  1. 6
    the fundamental assumptions from which something is begun or developed or calculated or explained wordnet

Example

More examples

"Make solidarity and equal rights the cornerstone of public policy."

Etymology

From Middle English corner ston; equivalent to corner + stone. The figurative sense is in part after Psalm 118:22, and is also quoted several times in the New Testament.

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.