Old part in Moonage Daydream (4)
I believe the answer is:
aged
'old' is the definition.
(similar in meaning)
'part in moonage daydream' is the wordplay.
'part in' indicates the answer is hidden within the clue.
'AGED' is hidden in the letters of 'moonage daydream'.
(Other definitions for aged that I've seen before include "Matured like wine in wood" , "Got older" , "Mature" , "Grew old" , "Antiquated" .)