Priestly garb
I believe the answer is:
alb
'priestly garb' 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 "Clerical vestment." , "White linen liturgical vestment" , "Long white church vestment" , "White clerical garment" , "Clerical gown" .)