Powder around stud (4)
I believe the answer is:
dust
'powder' is the definition.
(I've seen this before)
'around stud' is the wordplay.
'around' is an anagram indicator.
'stud' anagrammed gives 'DUST'.
(Other definitions for dust that I've seen before include "Microscopic particles in the air" , "Powdered matter" , "The mortal remains" , "Powdered eart" , "Fine dirt particles" .)