A-bomb vs fission bomb

A-bomb and fission bomb both are nouns.

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

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

A-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 A-bomb include atom bomb, atomic bomb, plutonium bomb.

A-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)