flying buttress

A flying buttress is a specific form of buttressing most strongly associated with Gothic church architecture. The purpose of any buttress is to resist the lateral forces pushing a wall outwards (which may arise from stone vaulted ceilings or from wind-loading on roofs) by redirecting them to the ground. The defining characteristic of a flying buttress is that the buttress is not in contact with the wall like a traditional buttress; lateral forces are transmitted across an intervening space between the wall and the buttress.