It may be ear-piercing (4)
I believe the answer is:
stud
'it may be ear-piercing' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for stud that I've seen before include "Part of a football boot" , "Football boot attachment" , "collection of cars" , "Boss; shirt fastener" , "kind of farm" .)