Puzzles, free, originally devised by the French (7)
I believe the answer is:
riddles
'puzzles' is the definition.
(I know this)
'by the french' is the wordplay.
'by' becomes 'ridd' (I can't explain this - if you can you should believe this answer much more).
'the french' becomes 'les' (plural form of 'the' in French).
'ridd'+'les'='RIDDLES'
'free originally devised' acts as a link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for riddles that I've seen before include "Word games or sieves" , "Tricky questions" , "problems" , "Coarse sieves or puzzles" , "Brain-teasers and coarse sieves" .)