Greek having drunk nectar goes into mysterious trance (6)
I believe the answer is:
cretan
'greek' is the definition.
(someone from the Greek island of Crete)
'mysterious trance' is the wordplay.
'mysterious' indicates an anagram.
'trance' is an anagram of 'CRETAN'.
'having drunk nectar goes into' acts as a link.
This may not be correct. Some or all of it may belong to another bit of the clue.
(Other definitions for cretan that I've seen before include "Inhabitant of a large Greek island" , "One from Greece's largest island" , "A Mediterranean islander" , "Native of a large Greek island" , "Greek islander" .)