Academy award recipient (4)

I believe the answer is:
alum
(Other definitions for alum that I've seen before include "Colourless compound used in dyeing and tanning" , "Compound used in dyeing and to stop bleeding" , "Sulphate; maul (anag.)" , "Sulphate used in dyeing and tanning" , "Potassium compound; IoW sandy bay" .)