The French express annoyance and maybe leer occasionally, arousing scorn (9)
I believe the answer is:
laughable
'arousing scorn' is the definition.
I can't judge whether this definition defines the answer.
'the french express annoyance and maybe leer occasionally' is the wordplay.
'the french express annoyance' becomes 'laugh' (I can't justify this - if you can you should give a lot more credence to this answer).
'and' is a charade indicator (letters next to each other).
'occasionally' means one should take alternating letters (letters taken at regular intervals or occasions).
'maybe'+'leer'='maybeleer'
The alternating letters of 'maybeleer' are 'able'.
'laugh'+'able'='LAUGHABLE'
Can you help me to learn more?
(Other definitions for laughable that I've seen before include "Risible, ridiculous" , "Ridiculous - make you chortle" , "Ludicrous" , "Ridiculous, derisory" , "Incongruous, inviting ridicule" .)