noun

• Fundamental knowledge or background in a field or discipline.
• The return to a fully conscious state after a psychedelic experience.
• The collision of a ship with ground beneath the surface of the water.
• The prevention of aircraft takeoff because of government action.
• (electrical engineering) The interconnecting metal chassis/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.
• The absorption of energy through visualized "roots" descending from oneself into the ground, using chi.
• The act by which a child is grounded (forbidden from going out, using electronics, etc.).
• The background of embroidery, etc.