arms vs munition

arms and munition both are nouns.

Word	Noun	Adjective	Verb	Adverb
arms	Yes	No	No	No
munition	Yes	No	Yes	No

As nouns, arms and munition are synonyms defined as:

Other synonyms of arms include implements of war, weaponry, weapons system.

arms (noun)	munition (noun)
weapons considered collectively	weapons considered collectively
the official symbols of a family, state, etc.	defensive structure consisting of walls or mounds built around a stronghold to strengthen it
	military supplies

arms (verb)	munition (verb)
	supply with weapons