Many converted by the French non-cleric (6)
I believe the answer is:
layman
'non-cleric' is the definition.
I can't judge whether this definition defines the answer.
'many converted by the french' is the wordplay.
'converted' indicates anagramming the letters.
'by' means one lot of letters go next to another.
'the french' becomes 'la' ('the' in French).
'many' is an anagram of 'yman'.
'yman' after 'la' is 'LAYMAN'.
Can you help me to learn more?
(Other definitions for layman that I've seen before include "member of the congregation" , "He's not a clergyman" , "He's not a cleric" , ""nonspecialist"" , "He's not ordained or professional" .)