noun Fundamental knowledge or background in a field or discipline.
noun The return to a fully conscious state after a psychedelic experience.
noun The collision of a ship with ground beneath the surface of the water.
noun The prevention of aircraft takeoff because of government action.
noun The interconnecting metal chassis or frame of a device, appliance, machine, or metal raceway via a designated conductor to earth at the service panel. It may be bare or covered, and does not carry current in normal operation.
noun The absorption of energy through visualized roots descending from oneself into the ground, using chi.
noun The act by which a child is grounded (forbidden from going out, using electronics, etc.).