Pine in Babylon gardens (4)
I believe the answer is:
long
'pine' is the definition.
(to pine for something is to long for it)
'in babylon gardens' is the wordplay.
'in' indicates a hidden word.
'LONG' is hidden within 'babylon gardens'.
(Other definitions for long that I've seen before include "Really want" , "summer break?" , "Lengthy - pine" , "Yearn (for)" , "Protracted" .)