Hostile fire one can and does get involved in (9)
I believe the answer is:
cannonade
'hostile fire one can and does get involved in' is the definition.
I can't judge whether this defines the answer.
'fire one can and does get involved in' is the wordplay.
'fire' becomes 'can' (dismiss from job).
'one can' is an anagram indicator (I've seen 'canned' mean this (canned can mean drunk)).
'does get involved' becomes 'noe' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'in' means one lot of letters goes inside another.
'and' with letters rearranged gives 'nad'.
'nad' put into 'noe' is 'nonade'.
'can'+'nonade'='CANNONADE'
Can you help me to learn more?
(Other definitions for cannonade that I've seen before include "Period of continuous heavy gunfire" , "Barrage" , "attack" .)