tumult vs combustion

tumult and combustion both are nouns.

Word	Noun	Adjective	Verb	Adverb
tumult	Yes	No	No	No
combustion	Yes	No	No	No

As nouns, combustion is a hyponym of tumult; that is, combustion is a word with a more specific, narrower meaning than tumult:

tumult (noun)	combustion (noun)
the act of making a noisy disturbance	the act of burning something
violent agitation	a process in which a substance reacts with oxygen to give heat and light
a state of commotion and noise and confusion	a state of violent disturbance and excitement