Denied the necessity to carry a gun (7)
I believe the answer is:
negated
'denied' is the definition.
(I've seen this in another clue)
'necessity to carry a gun' is the wordplay.
'necessity' becomes 'need' (synonyms).
'to carry' means one lot of letters goes inside another.
'a gun' becomes 'gat' (US informal term for a gun).
'need' going around 'gat' is 'NEGATED'.
'the' acts as a link.
(Other definitions for negated that I've seen before include "Nullified" , "Contradicted" , "Cancelled or destroyed the effect of something" , "Discredited" , "Made ineffective" .)