Witty reply about securing independent job (7)
I believe the answer is:
riposte
'witty reply' is the definition.
(I've seen this before)
'about securing independent job' is the wordplay.
'about' becomes 're' (regarding**).
'securing' is an insertion indicator.
'independent' becomes 'i'.
'job' becomes 'post' (post is a kind of job).
'i'+'post'='ipost'
're' placed around 'ipost' is 'RIPOSTE'.
(Other definitions for riposte that I've seen before include "Quick answer" , "Rejoinder" , "Sharp answer" , "Fencer's counterattack" , "Reply, retort" .)