Linen vestment (3)
I believe the answer is:
alb
'linen vestment' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for alb that I've seen before include "Long white robe worn by Christian priest" , "Clerical gown" , "ecclesiastical garment" , "Cover" , "Long white church vestment" .)