Cavorite is a substance that creates a limited antigravity field.
The material was either created or discovered by Helena G. Wells, and used in a fictional capacity in two of her novels. She also used it to power an actual antigravity generator in one room of her house in London. In 2010, she tricked Warehouse 13 agents Myka Bering and Peter Lattimer into activating the generator, resulting in their being flung into the ceiling while she remained floorbound with the use of magnetic boots.
Agent Lattimer subsequently overloaded the generator by firing a Tesla into the device.