Buff  —adj. Of a yellowish beige colour (buff envelope). —n. 1 this colour. 2 (in comb.) Colloq. Enthusiast (railway buff). 3 velvety dull-yellow ox-leather. —v. 1 polish (metal etc.). 2 make (leather) velvety.  in the buff colloq. Naked. [originally = buffalo, from french buffle]