Merriam-Webster's Collegiate® Dictionary, 11th Edition
BUFF
I. noun
Etymology: Middle French buffle wild ox, from Old Italian bufalo
Date: 1570
a garment (as a uniform) made of buff leather, the state of being nude ,
3. a moderate orange yellow, a light to moderate yellow, a device having a soft absorbent surface (as of cloth) by which polishing material is applied, fan , enthusiast ,
II. adjective
Date: 1746
of the color buff, having a physique enhanced by bodybuilding exercises,
III. transitive verb
Date: 1838
polish , shine , to give a velvety surface to (leather)