bomb vs arms

bomb and arms both are nouns.

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

As nouns, arms is a hypernym of bomb; that is, arms is a word with a broader meaning than bomb:

Other hypernyms of bomb include explosive device, implements of war, munition, weaponry, weapons system.

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

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