A slave upset husband again (6)
I believe the answer is:
afresh
'again' is the definition.
('afresh' can be a synonym of 'again')
'a slave upset husband' is the wordplay.
'slave' becomes 'serf' (I've seen this before).
'upset' shows that the letters should be reversed in order.
'husband' becomes 'h'.
'serf' reversed gives 'fres'.
'a'+'fres'+'h'='AFRESH'
(Other definitions for afresh that I've seen before include "In a different way" , "Newly" , "In a new way" , "Academy award" , "Anew, from the beginning" .)