Meaning

noun a support usually of stone or brick; supports the wall of a building

verb reinforce with a buttress

verb make stronger or defensible

originFrom Old French ars bouterez (noun, literally “supporting arcs”), from bouterez (adjective), oblique plural of bouteret (rare in the singular), from Frankish *bôtan, from Proto-Germanic *bautaną (“to push”). Ultimately cognate with beat.

Etymology from Wiktionary, CC BY-SA 3.0