One who’s fled bad regime? (6)
'one who's fled' is the definition.
(someone who has fled their home country)
'bad regime?' is the wordplay.
'bad' indicates anagramming the letters.
'regime' is an anagram of 'EMIGRE'.
(Other definitions for emigre that I've seen before include "One living abroad (to escape regime)", "One leaving country for political reasons", "Someone who leaves one country to settle in another", "Someone leaving the country for good", "Person forced to flee his country for political reasons".)