Dictionary and Thesaurus

Definition of Keystone

• (n.) 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.

Synonyms of Keystone

• Anchor
• Mainstay
• Backbone
• Linchpin
• Lynchpin
• Key
• Headstone

Antonyms of Keystone

Homophones of Keystone