Meaning

noun a process in which a substance reacts with oxygen to give heat and light

noun a state of violent disturbance and excitement

noun the act of burning something

originFrom Old French combustion, from Latin combustio, from comburere (“to burn”), itself from the intensifying prefix com- + the root burere (a faulty sep. of amburere "to burn around", itself from ambi- + urere "to burn, singe"); equivalent to combust + -ion.

Etymology from Wiktionary, CC BY-SA 3.0