plutonium bomb vs fission bomb

plutonium bomb and fission bomb both are nouns.

Word	Noun	Adjective	Verb	Adverb
plutonium bomb	Yes	No	No	No
fission bomb	Yes	No	No	No

As nouns, plutonium bomb and fission bomb are synonyms defined as:

plutonium bomb and fission 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 A-bomb, atom bomb, atomic bomb.

plutonium bomb (noun)	fission 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)