Approval, or permission to proceed.
A go-ahead to commit a crime, specifically to carry out a hit on someone (i.e. to kill).
A traffic light in its green state (indicating that vehicles may proceed).
Fundamental knowledge or background in a field or discipline.
The collision of a ship with ground beneath the surface of the water.
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 return to a fully conscious state after a psychedelic experience.
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 background of embroidery, etc.
The prevention of aircraft takeoff because of government action.