Telling stories — some only in Greek (5)
I believe the answer is:
lying
'telling stories' is the definition.
(I've seen this in another clue)
'some only in greek' is the wordplay.
'some' says the answer is hidden in the clue (some parts of the word are used).
'LYING' is hidden within 'only in greek'.
(Other definitions for lying that I've seen before include "Prone - mendacity" , "Telling untruths" , "Deviating from truth" , "Prostrate -- prone" , "Flat-out" .)