Go back over (7)
'go back over' is the definition.
(thesaurus)
This is the entire clue.
(Another definition for retrace that I've seen is " Go back over (one's steps)".)
(Other definitions for reread that I've seen before include "Give script second seeing to" , "look again at manifesto?" , "Study text again" , "Perused again" , "Peruse or scan again; it's dearer" .)