a buttress connected with a wall at some distance from it by an arch or part of an arch: it serves to resist outward pressure
An arched masonry support serving to bear thrust, as from a vaulted ceiling, away from a main structure to an outer pier or buttress. Also called arc-boutant.
Cathedral of Notre-Dame
(plural flying buttresses)
- (architecture) a buttress that stands apart from the structure that it supports, and is connected to it by an arch (flyer).