buttress

buttress \BUH-tris\, verb:

1. To give encouragement or support to (a person, plan, etc.).
2. To support by a buttress; prop up.

noun:
1. Any external prop or support built to steady a structure by opposing its outward thrusts, especially a projecting support built into or against the outside of a masonry wall.
2. Any prop or support.
3. A thing shaped like a buttress, as a tree trunk with a widening base.
4. A bony or horny protuberance, especially on a horse's hoof.

But that our cause, our very life and future hopes and past pride, should have been thrown into that balance with men like that to buttress it—men with valor and strength but without pity of honor.
-- William Faulkner, Absalom, Absalom!

It occurred to me that perhaps my brother gilder, Elegant, had with sly intent used these facts to buttress his false accusations.
-- Orhan Pamuk, My Name is Red

In its current form, buttress is a derivative of the Old French boteret, referring to 'support.'