Emigré upset by new government (7)
I believe the answer is:
regimen
'government' is the definition.
(I've seen this before)
'emigre upset by new' is the wordplay.
'upset by' indicates an anagram.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'emigre' with letters rearranged gives 'regime'.
'regime'+'n'='REGIMEN'
(Other definitions for regimen that I've seen before include "Method of working" , "recommended diet" , "That's what doctor orders" , "Disciplined system" , "Prescribed way of life like diet" .)