Drink on account of French honour (8)
I believe the answer is:
accolade
'honour' is the definition.
('accolade' can be a synonym of 'honour')
'drink on account of french' is the wordplay.
'drink' becomes 'cola' (I've seen this before**).
'on' means one lot of letters go next to another.
'account' becomes 'ac'.
'of french' becomes 'de'.
'cola' after 'ac' is 'accola'.
'accola'+'de'='ACCOLADE'
(Other definitions for accolade that I've seen before include "Praise publicly given" , "Acclaim; mark of honour" , "Praise, honour" , "Praise, or touch on shoulder to confer knighthood" , "Sign or expression of great praise or approval" .)