Rubbish in bed (4)
I believe the answer is:
bunk
I believe this clue is a double definition.
'rubbish' is the first definition.
(thesaurus)
'bed' is the second definition.
(bunk is a kind of bed)
'in' acts as a link.
(Other definitions for bunk that I've seen before include "Type of bed" , "Nonsense - hurried departure - bed" , "(Two-tier) bed - rubbish" , "History (said Henry Ford) - bed!" , "Hurried departure - place to sleep" .)