arms vs bomb

arms and bomb both are nouns.

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

As nouns, bomb is a hyponym of arms; that is, bomb is a word with a more specific, narrower meaning than arms:

arms (noun)	bomb (noun)
weapons considered collectively	an explosive device fused to explode under specific conditions
the official symbols of a family, state, etc.	strong sealed vessel for measuring heat of combustion
	an event that fails badly or is totally ineffectual

arms (verb)	bomb (verb)
	throw bombs at or attack with bombs
	fail to get a passing grade