Sound shortened in shout to encourage knight (9)
I believe the answer is:
chevalier
'knight' is the definition.
(I've seen this before)
'sound shortened in shout' is the wordplay.
'sound shortened' becomes 'vali' (I can't explain this - if you can you should give a lot more credence to this answer).
'in' is an insertion indicator.
'shout' becomes 'cheer' (I've seen this before).
'vali' placed within 'cheer' is 'CHEVALIER'.
'to encourage' acts as a 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 chevalier that I've seen before include "novelist" , "courteous type" , "young Charlie?" , "order of merit" , "Knight, gallant" .)