Get the wind: to smoke marijuana.

Goiter: Annoying twig-like bits in the mull, from cigarettes.
Go loco - to smoke marijuana.

Gootee: Ancient Chinese air layering technique.

Grief: Australian Cannabis leaf.

Groceries: Stash of cannabis.

Groper: A massive bong hit, followed by much coughing as your lungs grope for air.

Growlies: Craving for food while smoking marijuana.