† ˈcrustous,a.Obs. [a. OF.crousteus, mod. F. croûteux, ad. L. crustōs-us (Pliny), f.crusta crust.] Of the nature of a crust or scab; crusty. c1400Lanfranc's Cirurg. 350 Rotid fleisch & crustous.1651Biggs New Disp. ⁋238 Before the crustous eschar be taken away.