The total loss of hope of the French couple (7)
I believe the answer is:
despair
'the total loss of hope' is the definition.
(I've seen this before)
'of the french couple' is the wordplay.
'of the french' becomes 'des' ('of the' in French).
'couple' becomes 'pair' (synonyms).
'des'+'pair'='DESPAIR'
(Other definitions for despair that I've seen before include "Total loss of hope" , "Hopeless" , "gloom" , "Despond" , "sort of counsel?" .)