Clerical neckwear (3,6)
I believe the answer is:
dog collar
'clerical neckwear' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for dog collar that I've seen before include "part of religious outfit" , "Ecclesiastical" , "Six Dn neckwear (colloq.)" , "What churchmen assume" , "Clerical neckwear" .)