architecture a projecting structure of masonry or wood for supporting or giving stability to a wall or building.
projecting support built into or against a wall
any support
to support
to prop up [v BUTTRESSED, BUTTRESSES, BUTTRESSING]
A buttress is a structure built against a wall in order to support or strengthen it. More broadly, buttress may refer to anything that supports or strengthens. Buttress may also refer to something that resembles a buttress, such as a projecting part of a mountain or hill, a horny protuberance on a horse''s hoof at the heel, or the broadened base of a tree trunk or a thickened vertical part of it.