plutonium bomb vs A-bomb

plutonium bomb and A-bomb both are nouns.

Word	Noun	Adjective	Verb	Adverb
plutonium bomb	Yes	No	No	No
A-bomb	Yes	No	No	No

As nouns, plutonium bomb and A-bomb are synonyms defined as:

plutonium bomb and A-bomb: a nuclear weapon in which enormous energy is released by nuclear fission (splitting the nuclei of a heavy element like uranium 235 or plutonium 239)

Other synonyms of plutonium bomb include atom bomb, atomic bomb, fission bomb.

plutonium bomb (noun)	A-bomb (noun)
a nuclear weapon in which enormous energy is released by nuclear fission (splitting the nuclei of a heavy element like uranium 235 or plutonium 239)	a nuclear weapon in which enormous energy is released by nuclear fission (splitting the nuclei of a heavy element like uranium 235 or plutonium 239)