Definition

Noun: 1. The keystone of an arch: The central, wedge-shaped stone at the top of an arch that locks all the other stones in place. 2. An expandable metal or wooden wedge used by printers: A tool used in traditional printing to secure a block of type within a frame (called a chase) by applying pressure.

Examples of Usage

• As the keystone of an arch:
  • The ancient Roman aqueduct remained standing for centuries, its strength dependent on each perfectly carved coign.
  • The architect pointed out the intricately sculpted coign at the apex of the cathedral's doorway.
• As a printer's wedge:
  • The typesetter tightened the coigns to ensure the form would not shift during the press run.
  • Before the invention of modern printing, a mallet was used to tap the coign into place.

Advanced Usage

• Coign of vantage: This is a fixed literary phrase meaning a favorable position for observation or judgment. It originates from Shakespeare's (Act I, Scene VI).
  • From his balcony, he had a coign of vantage over the entire piazza.
  • Her experience in both departments gave her a unique coign of vantage on the company's problems.

Variants and Related Words

• Quoin (noun): This is the more common modern spelling for both architectural and printing meanings. "Coign" is an older variant.
  • The stone quoin at the corner of the building was decorative.
  • He adjusted the quoins in the chase.

Synonyms

• For the architectural meaning: keystone, headstone, capstone.
• For the printing meaning: wedge, locking wedge.

Notes on Different Meanings

The two primary meanings are connected by the core idea of a wedge-shaped object used to secure or lock something in place. In architecture, it secures an arch. In printing, it secures a form of type. The phrase "coign of vantage" is a specialized, metaphorical use derived from the architectural concept of a strategic, elevated position.

Noun

1. the keystone of an arch
2. expandable metal or wooden wedge used by printers to lock up a form within a chase