Arms injunction I ignored (8)
I believe the answer is:
ordnance
'arms' is the definition.
(ordnance is a kind of arms)
'injunction i ignored' is the wordplay.
'injunction' becomes 'ordinance'.
'ignored' suggests deleting specific letters.
'ordinance' with 'i' taken out is 'ORDNANCE'.
(Other definitions for ordnance that I've seen before include "Arsenal's big guns" , "weaponry" , "Survey may follow this" , "Anne Cord is in military supplies" , "guns etc." .)