Meaning

• A brick or stone structure built against another structure to support it.

• Anything that serves to support something; a prop.

• A buttress-root.

• A feature jutting prominently out from a mountain or rock; a crag, a bluff.

• Anything that supports or strengthens.

Meaning

• To support something physically with, or as if with, a prop or buttress.

• (by extension) To support something or someone by supplying evidence; to corroborate or substantiate.