English to English

noun (n)

• a central cohesive source of support and stability

  pusat berpaut sumber sokongan dan stabilitas

  Example:
  The keystone of campaign reform was the ban on soft money.
  

  Synonym:
  anchor, backbone, linchpin, lynchpin, mainstay
  

  source: wordnet30
• the central building block at the top of an arch or vault

  pusat blok bangunan di puncak yang melengkung atau besi

  Synonym:
  headstone, key
  

  source: wordnet30
• The central or topmost stone of an arch. This in some styles is made different in size from the other voussoirs, or projects, or is decorated with carving. See Illust. of Arch.

  pusat atau paling batu yang melengkung. ini dalam beberapa gaya dibuat dalam saiz berbeza dari yang lain voussoirs, atau projek, atau dihiasi dengan ukiran. lihat aku illust. / aku dari u arch/ u.

  source: webster1913