A sudden uncontrolled increase.
A sudden outburst.
A violent release of energy (sometimes mechanical, nuclear, or chemical.)
A bursting due to pressure.
The sound of an explosion.
The condition or state being recrudescent; the condition of something (often undesirable) breaking out again, or re-emerging after temporary abatement or suppression.
The production of a fresh shoot from a ripened spike.
The acute recurrence of a disease, or its symptoms, after a period of improvement.