Priestly garment (3)
I believe the answer is:
alb
'priestly garment' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for alb that I've seen before include "Priests robe made in Balbriggan" , "Long white church vestment" , "Priestly garment" , "Priest's long white sleeved vestment" , "the vicar might put on?" .)