combustion vs kindling

combustion and kindling both are nouns.

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

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

Other hyponyms of combustion include arson, fire-raising, incendiarism, firing, ignition, inflammation, lighting, incineration.

combustion (noun)	kindling (noun)
the act of burning something	the act of setting something on fire
a process in which a substance reacts with oxygen to give heat and light	material for starting a fire
a state of violent disturbance and excitement