Set off late (8)
I believe the answer is:
departed
I believe this clue is a double definition.
'set off' is the first definition.
(to set off is to leave or depart)
'late' is the second definition.
(I've seen this before)
(Other definitions for departed that I've seen before include "Gone, maybe dead" , "Quit" , "Left -- late" , "Dead; set off" , "Went - dead" .)