Ideal state without opiates, in part (6)
I believe the answer is:
utopia
'ideal state' is the definition.
(I've seen this before)
'without opiates in part' is the wordplay.
'in part' says the answer is hidden in the clue.
'UTOPIA' is hidden in the letters of 'without opiates'.
(Other definitions for utopia that I've seen before include "Perfect world?" , "Sir Thomas Moore's perfect society" , "Eden" , "Idyllic land" , "Sir Thomas More's perfect place" .)