Ignore girl making a weapon (7)
I believe the answer is:
cutlass
'a weapon' is the definition.
(cutlass is a kind of weapon)
'ignore girl' is the wordplay.
'ignore' becomes 'cut' (synonyms).
'girl' becomes 'lass' (lass can informally mean a girl).
'cut'+'lass'='CUTLASS'
'making' acts as a link.
(Other definitions for cutlass that I've seen before include "Sword formerly used by sailors" , "Short, broad-bladed sword" , "Curved, one-edged sword" , "could hurt one, in the main" , "Piratical sword" .)