Priest's garment (3)
I believe the answer is:
alb
'priest's 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 "Devotional vestment" , "Priests robe made in Balbriggan" , "Priest's long white sleeved vestment" , "Long white robe worn by Christian priest" , "ecclesiastical garment" .)