combust vs fire

combust is not a noun while fire is a noun.

Word	Noun	Adjective	Verb	Adverb
combust	No	No	Yes	No
fire	Yes	No	Yes	No

combust (noun)	fire (noun)
	the act of firing weapons or artillery at an enemy
	a fireplace in which a relatively small fire is burning
	intense adverse criticism
	the event of something burning (often destructive)
	a severe trial
	feelings of great warmth and intensity
	the process of combustion of inflammable materials producing heat and light and (often) smoke
	fuel that is burning and is used as a means for cooking
	once thought to be one of four elements composing the universe (Empedocles), associated with the humour bile

combust (verb)	fire (verb)
undergo combustion	bake in a kiln so as to harden
get very angry and fly into a rage	destroy by fire
cause to become violent or angry	start or maintain a fire in
start to burn or burst into flames	become ignited
cause to burn or combust	cause to go off
	start firing a weapon
	go off or discharge
	generate an electrical impulse
	call forth (emotions, feelings, and responses)
	drive out or away by or as if by fire
	provide with fuel
	terminate the employment of; discharge from an office or position