Denied of weapon in need (7)
I believe the answer is:
negated
'denied' is the definition.
(I've seen this in another clue)
'weapon in need' is the wordplay.
'weapon' becomes 'gat' (gat is a kind of weapon).
'in' means one lot of letters goes inside another.
'gat' put into 'need' is 'NEGATED'.
'of' acts as a link.
(Other definitions for negated that I've seen before include "Nullified" , "Made ineffective" , "Denied" , "Discredited" , "Abrogated" .)