Slaughter husband in bunk (6)
I believe the answer is:
thrash
'slaughter' is the definition.
(both can mean to beat decisively)
'husband in bunk' is the wordplay.
'husband' becomes 'h'.
'in' indicates putting letters inside.
'bunk' becomes 'trash' (both can mean rubbish).
'h' put inside 'trash' is 'THRASH'.
(Other definitions for thrash that I've seen before include "Administer severe beating to" , "worst > party" , "stuff" , "Soundly defeat; party" , "Best" .)