Emigré created by collapse of this government (6)
I believe the answer is:
regime
'government' is the definition.
('regime' can be a synonym of 'government')
'emigre created by collapse of this' is the wordplay.
'created by collapse of this' indicates anagramming the letters.
'emigre' is an anagram of 'REGIME'.
(Other definitions for regime that I've seen before include "Command" , "Emigre (anag.)" , "Government, especially an authoritarian one" , "Government - administration" , "Routine" .)