Part in saga incoherent once more (5)
I believe the answer is:
again
'once more' is the definition.
(synonyms)
'part in saga incoherent' is the wordplay.
'part in' says the answer is hidden in the clue.
'AGAIN' can be found hidden inside 'saga incoherent'.
(Other definitions for again that I've seen before include "Moreover - a second time" , "Not for the first time" , "second term" , "Here we go ___" , "10 10 [AGAIN" .)