(of a fluid) brought to a temperature and pressure higher than its critical temperature and pressure, so that its physical and chemical properties change
2. nuclear physics
of or containing more than the critical mass
supercritical in American English
(ˌsupərˈkrɪtɪkəl)
adjective
1. Chemistry
designating or of a fluid at a temperature greater than its critical temperature
2. Nuclear Physics
designating or of a highly unstable mass of fissionable material in which the total number of free neutrons and the rate of fission increase with time