Relating to a wedding (7)
I believe the answer is:
nuptial
'relating to a wedding' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for nuptial that I've seen before include "Relating to matrimony" , "Marital" , "To do with marriage or a wedding ceremony" , "Relating to marriage" , "Relating to weddings" .)