Soldier quick to learn about unserviceable gear (9)
I believe the answer is:
apparatus
'gear' is the definition.
(I've seen this before)
'soldier quick to learn about unserviceable' is the wordplay.
'soldier' becomes 'para' (para is a kind of soldier).
'quick to learn' becomes 'apt' (I can't explain this - if you can you should believe this answer much more).
'about' indicates putting letters inside.
'unserviceable' becomes 'us' (abbreviation).
'para' put within 'apt' is 'apparat'.
'apparat'+'us'='APPARATUS'
Can you help me to learn more?
(Other definitions for apparatus that I've seen before include "Tackle" , "Technical equipment" , "Piece of equipment" , "Equipment, device" , "Equipment, gear" .)