Participant in an exodus (8)
I believe the answer is:
emigrant
'participant in an exodus' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for emigrant that I've seen before include "One settling abroad" , "Write carelessly" , "Time Gran went abroad to settle" , "One going abroad permanently" , "I've left home for good" .)