A stone wall built against a wall to support the building is an example of a buttress.
- The flared base of certain tree trunks.
When a wall is providing support for a building, this is an example of a situation where the wall is a buttress for the building.
When a fact supports a position or argument, this is an example of a fact that is a buttress for the argument.
Origin of buttress
- Middle English buteras from Old French bouterez from bouter to strike against of Germanic origin bhau- in Indo-European roots
From American Heritage Dictionary of the English Language, 5th Edition