Copy expected decay (6)
I believe the answer is:
parrot
'copy' is the definition.
(I've seen this in another clue)
'expected decay' is the wordplay.
'expected' becomes 'par' (as in 'par for the course').
'decay' becomes 'rot' (rot can mean to decay).
'par'+'rot'='PARROT'
(Other definitions for parrot that I've seen before include "Brightly coloured bird that mimics speech" , "Tropical bird to repeat mindlessly" , "Raucous bird" , "Imitative bird" , "Mechanically repeat; bird" .)