Firing international, into gin unfortunately (8)
I believe the answer is:
ignition
'firing' is the definition.
('ignition' can be a synonym of 'firing')
'international into gin unfortunately' is the wordplay.
'international' becomes 'i' (abbreviation eg in IMF).
'unfortunately' indicates an anagram.
'into'+'gin'='intogin'
'intogin' is an anagram of 'gnition'.
'i'+'gnition'='IGNITION'
(Other definitions for ignition that I've seen before include "Act of catching fire" , "The purpose of the spark" , "Act of setting something on fire" , "Mechanism to start car engine by sparking fuel" , "The starting of car engine" .)