Buttress – meaning of the word and example

A structure made of stone or brick that sticks out from and supports a wall of a building. (Cambridge Dictionary)

A projecting structure of masonry or wood for supporting or giving stability to a wall or building. (Merriam – Webster)

A structure of stone or brick built against a wall to strengthen or support it. (Oxford Dictionaries)

Buttresses are supports, usually made of stone or brick, that support a wall. (Collins Dictionary)

Example

Buttress meaning in Cambridge Dictionary

Two buttresses supporting the walls of All Saints’ medieval parish church, Hempstead, Norfolk, UK.

https://dictionary.cambridge.org/dictionary/english/buttress