A sudden large increase or advance:
— This may not insure success but it will represent a quantum leap from last summer.

synonym: quantum jump.

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