Synonyms: supercritical
Definition: (especially of fissionable material) able to sustain a chain reaction in such a manner that the rate of reaction increases
Similar words: critical
Definition: at or of a point at which a property or phenomenon suffers an abrupt change especially having enough mass to sustain a chain reaction
Usage: a critical temperature of water is 100 degrees C--its boiling point at standard atmospheric pressure; critical mass; go critical