Greatly appreciating French wine, as recorded in diary (6)
I believe the answer is:
loving
'greatly appreciating' is the definition.
(to love something is to appreciate it greatly)
'french wine as recorded in diary' is the wordplay.
'french wine' becomes 'vin' ('wine' in French).
'as recorded in' means one lot of letters goes inside another.
'diary' becomes 'log' (log can mean a record or diary).
'vin' going into 'log' is 'LOVING'.
(Other definitions for loving that I've seen before include "Showing great affection" , "Doting" , "Affectionate and amorous" , "'Friday's child is . . . . . . and giving'" , "See 13" .)