1(of a reaction or process) accompanied by the release of heat.The opposite of endothermic
- ‘For these exothermic processes, the solubility decreases with an increase in temperature.’
- ‘The rusting of iron is an exothermic reaction and this process is used in hand warmers which are utilized in cold regions.’
- ‘Sodium hydroxide dissolved into water is an exothermic process, ammonium nitrate dissolved in water is an endothermic process.’
- ‘Inside the mold, the liquid undergoes an exothermic chemical reaction, which forms the polyurethane polymer in the mold.’
- ‘When fireworks are ignited, the chemical compounds react with each other in an exothermic reaction - releasing energy.’
- 1.1(of a compound) formed from its constituent elements with a net release of heat.
- ‘Little heat is needed in the roasting of sulfide ores because the oxidation of the sulfide ion to sulfur dioxide is exothermic.’
Late 19th century: from French exothermique.