Cockney's wish to get allocation of surgery (9)
I believe the answer is:
operation
'surgery' is the definition.
(I know that surgery can be written as operation)
'cockney's wish to get allocation' is the wordplay.
'cockney's wish' becomes 'ope' ('hope' - hoping is a kind of wishing - said with the 'H' dropped - a cockney accent.).
'to get' says to put letters next to each other.
'allocation' becomes 'ration' (I've seen this before).
'ope'+'ration'='OPERATION'
'of' acts as a link.
(Other definitions for operation that I've seen before include "battle" , "Theatre procedure" , "financial transaction" , "Handling" , "Action; process" .)