Sad passage to quote back (8)
I believe the answer is:
pathetic
'sad' is the definition.
(I've seen this in another clue)
'passage to quote back' is the wordplay.
'passage' becomes 'path' (I've seen this in other clues).
'to quote' becomes 'cite' ('cite' can be a synonym of 'quote').
'back' is a reversal indicator.
'cite' reversed gives 'etic'.
'path'+'etic'='PATHETIC'
(Other definitions for pathetic that I've seen before include "arousing contempt" , "Poor" , "Tip cheat - truly sad" , "Sort of fallacy" , "Contemptible" .)