Put on grave attire? (8)
I believe the answer is:
enshroud
'attire?' is the definition.
(thesaurus)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for enshroud that I've seen before include "Cover with a garment (or mist?)" , "Hide - cloak" , "Completely envelop" , "Envelop and hide from view" .)