Masking (7)
(Other definitions for veiling that I've seen before include "Clump (of grass, hair, etc)" , "Hiding" , "Shrouding" , "Vile gin (anag.)" .)
'masking' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for hiding that I've seen before include "Physical beating" , "going underground" , "Beating - retreat" , "Not exposing" , "physical punishment" .)