Farewell from police officer in a multinational group (5)
I believe the answer is:
adieu
'farewell' is the definition.
(adieu is a kind of farewell)
'police officer in a multinational group' is the wordplay.
'police officer' becomes 'DI' (abbreviation for Detective Inspector).
'in' means one lot of letters goes inside another.
'multinational group' becomes 'eu' (I can't justify this - if you can you should believe this answer much more).
'a'+'eu'='aeu'
'di' put into 'aeu' is 'ADIEU'.
'from' acts as a link.
Can you help me to learn more?
(Other definitions for adieu that I've seen before include "Farewell, ami!" , "See you later" , "Vale" , "Farewell (French)" , "Farewell to France" .)