A bit of ammunition in the vicinity (6)
I believe the answer is:
around
'in the vicinity' is the definition.
(synonyms)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for around that I've seen before include "Close to" , "Here and there; encircling" , "About, here and there in circular way?" , "Present; approximately" , "On every side" .)