Left again (4)
I believe the answer is:
over
I believe this clue is a double definition.
'left' is the first definition.
(thesaurus)
'again' is the second definition.
(as in the phrases 'start over' and 'start again')
(Other definitions for over that I've seen before include "Excessive" , "Past, surplus" , "jumped fence" , "Given too much money" , "See 23" .)