Such a little record is compact (4)
I believe the answer is:
disc
'such a little record is compact' is the definition.
I can't judge whether this defines the answer.
'a little record is compact' is the wordplay.
'a little' says the answer is hidden in the clue.
'DISC' is hidden within 'record is compact'.
(Other definitions for disc that I've seen before include "Circle" , "45, eg?" , "put on by jockey?" , "CD perhaps" , "One of 33, 45 or 78?" .)