architectural structure, usually of masonry, built to strengthen or support walls or resist the lateral thrust of vaults
A buttress is a structure placed against the walls of a building to give it more support, or to help it to hold the roofs. Buttresses are common in ancient buildings, especially in Europe. A buttress can be an inside or outside support.
|Wikisource has the text of the 1911 Encyclopædia Britannica article Buttress.|