tsunami

noun2

1. •
   A very large and destructive wave, generally caused by a tremendous disturbance in the ocean, such as an undersea earthquake or volcanic eruption; often a series of waves (a wave train).

   • A tsunami struck Japan recently.
2. •
   (figurative) A large and generally unstoppable surge.

   • It seemed that what started out as a handful of isolated cases gradually turned into a tsunami of complaints. — 2009