Definition of keystone in US English:



  • 1A central stone at the summit of an arch, locking the whole together.

    • ‘An archway's most important stone is the keystone, the wedge-shaped piece of rock at its apex.’
    • ‘It has to be remembered that even repeated patterns round a window required different models for each side, as well as for the voussoirs, keystone, and stop-ends, each of which had to be specially drawn.’
    • ‘The final seven rusticated bands are precisely linked to the voussoirs and keystones that define the arches and the niches, the latter exactly the same height as the rectangular openings below.’
    • ‘The building features window keystones, coloured tiles, and heavy overhanging cornices.’
    • ‘Other features of this family home include its brick finish with granite keystones, reconstituted granite sills, top of the range sanitary ware, solid teak doors, as well as phone connections and TV wiring in all of the bedrooms.’
    • ‘The windows are surmounted by rusticated wooden jack arches with superimposed keystones, and a heavy modillion cornice crowns the bold Georgian proportions of the facade.’
    • ‘The keystones of the arches bear inscriptions indicating their precise location within the structure.’
    • ‘The keystone is the central cohesive source of support for the greater whole.’
    • ‘With a thickness of 12 inches, the arch features a decorative keystone and double corbels, outlined by antique glazing on a white lacquer base.’
    • ‘Naturalistic animals were carved on misericords in the early 14th century, and individualized facial features appeared on the small human heads that decorated keystones and arch mouldings.’
    • ‘Copper-top bays, corner quoins, paned windows, shutters and arches with decorative keystones above windows and doors are all features common in French-style homes.’
    • ‘True structural stepped arches with cast stone plinth block, spring line bases, and keystone are the focus of the main entry courtyard beyond the cast stone stair and ramp.’
    • ‘Each wall contains a walk-through arch marked by massive keystones that were hand worked onsite.’
    • ‘The building's exterior is largely unchanged, except that the carved mammal heads on the keystones of the first floor windows have been removed.’
    cornerstone, central stone, quoin
    View synonyms
    1. 1.1usually in singular The central principle or part of a policy, system, etc., on which all else depends.
      ‘cooperation remains the keystone of the government's security policy’
      • ‘He is the alpha and the omega, the principle and the end, the foundation stone and the keystone, the plenitude and the plenifier.’
      • ‘They can also question peers and learn how asking for and giving assistance to one another are keystones to academic success.’
      • ‘More and more, I have come to believe that the keystone of the whole process is the set of beliefs within the employee population.’
      • ‘The powerful myth of the dangers of protectionism is one of the philosophical keystones of today's globalisation model.’
      • ‘The hotel is a keystone of the master plan to rejuvenate Trenton.’
      • ‘The keystone of Indonesia's political system, rooted in the constitution of 1945, is a strong presidency.’
      • ‘Property rights, of course, form one of the keystones of the Anglosphere system.’
      • ‘People and the planet on which we live should be the primary referents of security in the 21st century, and human and global security should be the keystones of Australia's foreign and defence policies.’
      • ‘Risk management and evidence based medicine are keystones of clinical governance.’
      • ‘The interaction of classes, genders, and generations, and social keystones like marriage, family, and parenthood, experienced massive strains and became less structured.’
      • ‘The keystone of a strong trademark policy is proper selection of trademarks.’
      • ‘This win-win strategy is the keystone of the economic policy framework of the Government.’
      • ‘The patriarchal conjugal family, man and wife, each acting within their proper sphere, and the containment of sexuality within legal matrimony, became the keystones of social stability and moral progress.’
      • ‘Louis Pasteur, sometimes regarded as the father of modern medicine, put forward the germ theory of disease, which set the foundation for disinfection and vaccination as keystones for disease management.’
      • ‘China is among the top investors in this technology, not just because these plants are much cleaner, but also because they could be keystones in a program to synthesize clean liquid fuels for transportation needs.’
      • ‘Training, skill, and specialization became the keystones of professional baseball.’
      • ‘We must be careful, however, not to paint a picture of historical evidence that suggests that newspapers are the keystones of such documentation.’
      • ‘They had begun to realize that, should the king abscond, the keystone of the whole constitution would be lost, with incalculable consequences.’
      • ‘It is already a keystone of the school and the neighborhood, and it represents a rare and welcome realization of the socializing potential of buildings.’
      • ‘So the keystone to the whole enterprise is getting the body in balance.’
      foundation, basis, linchpin, cornerstone, base, principle, guiding principle, core, heart, centre, crux, fundament, mainspring, priority
      View synonyms