The Greens, perhaps, making comeback in Caerwys, N Wales (5)
I believe the answer is:
lawns
'the greens' is the definition.
'comeback in caerwys n wales' is the wordplay.
'comeback' is a reversal indicator.
'in' says the answer is hidden in the clue.
'snwal' is hidden in the letters of 'caerwys n wales'.
'snwal' backwards is 'LAWNS'.
'perhaps making' acts as a link.
(Other definitions for lawns that I've seen before include "Areas of mown grass" , "grasses" , "that need cutting" .)