quebracho UK /kɪˈbɹɑːt͡ʃəʊ/US /kɛˈbɹɑt͡ʃoʊ/ noun4 •Any of several trees of southern South America with produce very hard wood rich in tannin, especially those of the genus Schinopsis. •The wood of these trees. •A tannin extracted from these trees. •The bark of these trees, formerly used in treating fever. formsquebrachos