Relating to weddings (7)
I believe the answer is:
nuptial
'relating to weddings' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for nuptial that I've seen before include "Relating to matrimony" , "Until pa (anag.)" , "Like wedding ceremony" , "Pertaining to weddings" , "Matrimonial" .)