uprush

From The Collaborative International Dictionary of English v.0.48:

Uprush \Up*rush"\, v. i.
   To rush upward. --Southey.
   [1913 Webster]
.

From The Collaborative International Dictionary of English v.0.48:

Uprush \Up"rush`\, n.
   Act of rushing upward; an upbreak or upburst; as, an uprush
   of lava. --R. A. Proctor.
   [1913 Webster]