Imitate equal rubbish (6)
I believe the answer is:
parrot
'imitate' is the definition.
(I've seen this in another clue)
'equal rubbish' is the wordplay.
'equal' becomes 'par'.
'rubbish' becomes 'rot' (both can mean nonsense).
'par'+'rot'='PARROT'
(Other definitions for parrot that I've seen before include "Unintelligent imitator" , "Sick as a -" , "Brightly-coloured tropical bird" , "Mimic speech like colourful bird" , "Raucous bird" .)