Article in French with heading that's clear (7)
I believe the answer is:
unbound
'clear' is the definition.
(thesaurus)
'article in french with heading' is the wordplay.
'article in french' becomes 'un' (an indefinite article in French).
'with' is a charade indicator (letters next to each other).
'heading' becomes 'bound' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'un'+'bound'='UNBOUND'
'that's' acts as a link.
Can you help me to learn more?
(Other definitions for unbound that I've seen before include "Loose" , "Prometheus ... (Shelley)" , "Not restricted" , "Like Shelley's Prometheus" .)