physics An abrupt transition of an electron or atom or molecule from one quantum state to another with the emission or absorption of a quantum.

A sudden large increase or advance.

synonym: quantum leap.

Roget 146: revolution, bouleversement, subversion, break up; destruction etc. 162; sudden change, radical change, sweeping organic change; change of state, phase change; quantum leap, quantum jump; clean sweep, coup d'etat [Fr.], counter revolution.    jump, leap, plunge, jerk, start, transilience^†; explosion; spasm, convulsion, throe, revulsion; storm, earthquake, cataclysm.    legerdemain etc. (trick) 545.    ... show more