Some rubbish in this clue (4)
I believe the answer is:
hint
'clue' is the definition.
(synonyms)
'some rubbish in this' is the wordplay.
'some' says the answer is hidden in the clue (some of the parts of the word are used).
'HINT' can be found hidden inside 'rubbish in this'.
(Other definitions for hint that I've seen before include "Taste" , "Tip, clue" , "Tip - small amount" , "Indicate indirectly" , "A dash" .)