Clerical vestment
'clerical vestment' 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 "Cover" , "Long white church vestment" , "Clerical vestment." , "the vicar might put on?" , "White linen liturgical vestment" .)
(Other definitions for cassock that I've seen before include "Is it a habit of the clergy" , "Long clerical robe" , "Clergyman's robe" , "Long garment worn by some clergy" , "Vestment" .)