Advocate English article following French article (7)
I believe the answer is:
apostle
'advocate' is the definition.
(the apostles were advocates of Jesus)
'english article following french article' is the wordplay.
'english article' becomes 'a' (indefinite article in English).
'following' becomes 'post' (eg post-war, post-industrial etc).
'french article' becomes 'le' (definite article in French).
'a'+'post'+'le'='APOSTLE'
(Other definitions for apostle that I've seen before include "Vigorous supporter" , "Teacher of new faith or movement" , "[JAMES] , for one?" , "Thaddeus, perhaps" , "A preacher of gospels" .)