combustion

Etymology

From 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.

noun

1. (chemistry) The act or process of burning.
2. A process whereby two chemicals are combined to produce heat.
3. A process wherein a fuel is combined with oxygen, usually at high temperature, releasing heat.
4. (figurative) Violent agitation, tumult.
   There [were] great combustions and divisions among the heads of the university. c. 1665, John Worthington, “The Works of the Pious and Profoundly-learned Joseph Mede”, in Life, The Author