Final answer:
A flying buttress is an external support built to stabilize a structure by opposing its outward thrusts, especially in masonry walls. It consists of vertical buttresses and arches called flyers that redirect forces and help prevent wall collapse.
Step-by-step explanation:
In architecture, an external support built to stabilize a structure by opposing its outward thrusts, especially a projecting support built into or against the outside of a masonry wall is called a flying buttress. This architectural element became popular during the Gothic era and played a crucial role in supporting the weight of high walls and redirecting the forces from the pointed arches to the ground. Flying buttresses consist of vertical supports called buttresses and arches called flyers that connect the buttresses to the walls they support. They help stabilize the walls and prevent them from collapsing due to the outward pressure.