Rubbish written about husband's party (6)
I believe the answer is:
thrash
'party' is the definition.
(thrash can informally mean a party)
'rubbish written about husband's' is the wordplay.
'rubbish' becomes 'trash' (synonyms).
'written about' indicates putting letters inside.
'husband' becomes 'h'.
'trash' enclosing 'h' is 'THRASH'.
(Other definitions for thrash that I've seen before include "Beat severely or defeat thoroughly" , "Beat up, batter" , "Administer severe beating to" , "Best" , "Beat violently" .)