buttress UK /ˈbʌtɹəs/US /ˈbʌtɹɪs/noun 5verb 2forms 3 noun5 •A brick, concrete or stone structure built against another structure to support it. •Anything that serves to support something; a prop. •A buttress root. •(figurative) Anything that supports or strengthens. •A feature jutting prominently out from a mountain or rock.Crowell Buttresses, Dismal Buttress verb2 •To support something physically with, or as if with, a prop or buttress. •(figurative) To support something or someone by supplying evidence. formsbuttressed · buttressing · buttresses