suppressive fire vs firing

suppressive fire and firing both are nouns.

Word	Noun	Adjective	Verb	Adverb
suppressive fire	Yes	No	No	No
firing	Yes	No	No	No

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

suppressive fire: fire on or about a weapon system to degrade its performance below what is needed to fulfill its mission objectives
firing: the act of firing weapons or artillery at an enemy

Other hypernyms of suppressive fire include fire.

suppressive fire (noun)	firing (noun)
fire on or about a weapon system to degrade its performance below what is needed to fulfill its mission objectives	the act of setting something on fire
	the termination of someone's employment (leaving them free to depart)
	the act of discharging a gun
	the act of firing weapons or artillery at an enemy