arc-boutant

Meaning

An external masonry structure consisting of an inclined bar carried on a half arch that extends from the upper portion of a wall to a heavy pier, designed to transmit the outward thrust of a roof or vault to the ground.

Examples

• The Gothic architect relied on the arc-boutant to allow for taller walls and larger stained-glass windows.
• Without the support of each arc-boutant, the cathedral's ceiling would have collapsed under its own weight.