Puzzle, free, originally devised by the French (6)
I believe the answer is:
riddle
'puzzle' is the definition.
(a riddle is a puzzle or problem)
'by the french' is the wordplay.
'by' becomes 'ridd' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'the french' becomes 'le' ('the' in French).
'ridd'+'le'='RIDDLE'
'free originally devised' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for riddle that I've seen before include "sort out" , "Run through" , "Screen" , "Cryptic statement" , "It may have an answer" .)