Funny comeback from comic in original piece (6)
I believe the answer is:
ironic
'funny' is the definition.
(I've seen this before)
'comeback from comic in original piece' is the wordplay.
'comeback' says the letters should be written backwards.
'from' indicates the answer is hidden within the clue.
'cinori' is hidden within 'comic in original piece'.
'cinori' reversed gives 'IRONIC'.
(Other definitions for ironic that I've seen before include "Cruelly humorous" , "Wryly satirical" , "Sarcastic, expressing meaning by invoking opposite" , "not as you'd expect" , "Double-edged" .)