The noun buttress means a structure, usually made of stone or brick, that supports a wall. The verb buttress means to give support to someone or something.
Synonyms are brace, column, reinforce, or strengthen.
The word origins from Old French (ealy 14th century) botrez meaning “flying buttress”, apparently from bouter, boter meaning “to thrust against”, a word of Frankish origin (compare Old Norse bauta meaning “to strike, beat”). Its figurative meaning “any source of support” is from mid-15th century.
I’m not a pillar of this company, but merely a buttress.
Their arguments are buttressed by the existing political turbulence in the country.
I saw her at the park with her books sitting on a concrete buttress.