salvo vs firing

salvo and firing both are nouns.

Word	Noun	Adjective	Verb	Adverb
salvo	Yes	No	No	No
firing	Yes	No	No	No

As nouns, firing is a hypernym of salvo; that is, firing is a word with a broader meaning than salvo:

Other hypernyms of salvo include fire.

salvo (noun)	firing (noun)
rapid simultaneous discharge of firearms	the act of setting something on fire
a sudden outburst of cheers	the termination of someone's employment (leaving them free to depart)
an outburst resembling the discharge of firearms or the release of bombs	the act of discharging a gun
	the act of firing weapons or artillery at an enemy