Cushions in flats? (4)
I believe the answer is:
pads
I believe this is a double definition.
'cushions' is the first definition.
(I've seen this in another clue)
'flats?' is the second definition.
(I've seen this before)
'in' acts as a link.
(Other definitions for pads that I've seen before include "Protective guards worn by sportspeople" , "Fleshes out" , "Quarters" , "flats?" , "Blocks" .)