1Above a critical threshold.

1. 1.1 (in nuclear physics) containing or involving more than the critical mass.
   Example sentencesExamples

   • The simplest atomic bomb works when two pieces of supercritical Uranium - 235 are brought together at speed.
   • After this supercritical mass is obtained, a self-sustained chain reaction takes place and causes the atomic explosion.
2. 1.2 (of a flow of fluid) faster than the speed at which waves travel in the fluid.
3. 1.3 Denoting an aerofoil or aircraft wing designed to tolerate shock-wave formation at transonic speeds.
4. 1.4 Relating to or denoting a fluid at a temperature and pressure greater than its critical temperature and pressure.
   Example sentencesExamples

   • The availability of experimental data for this reaction using cutinase in acetonitrile and supercritical CO2 has prompted this choice.
   • But there's plenty of ammonia out there, too, along with methane, sulfuric acid, and other potential solvents like the supercritical dihydrogen found in the lower layers of gas giant planets.
   • ‘With supercritical fluid extraction, we compress and heat a gas - usually carbon dioxide - so it becomes more dense and liquidlike,’ King explains.
   • ‘Chemists are attempting to address this problem by finding alternative solvents, such as water and supercritical CO2, and by biphasic system that allows catalyst recycling.’