Goodbye to a French deity (5)

I believe the answer is:

adieu

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'goodbye' is the definition.
(synonyms)

'a french deity' is the wordplay.
'french deity' becomes 'dieu' (I can't justify this - if you can you should believe this answer much more).
'a'+'dieu'='ADIEU'

'to' acts as a link.

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(Other definitions for adieu that I've seen before include "Goodbye, monsieur" , "Auf wiedersehen" , "Fare thee well!" , "Farewel" , "Goodbye, mademoiselle" .)

I've seen this clue in The Mirror.

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