Taken from Ganymede napping in garden (4)
I believe the answer is:
eden
'garden' is the definition.
(I've seen this before)
'taken from ganymede napping in' is the wordplay.
'taken from' says the answer is hidden in the clue.
'EDEN' is hidden within 'ganymede napping in'.
(Other definitions for eden that I've seen before include "Former British PM - unspoilt paradise" , "(Biblical) paradise" , "Adam and Eve's 19" , "heavenly spot" , "Idyllic garden" .)