when one is high and can see through everyone's fake shit. When you are so high you become incredibly insightful and deeply analyze those surrounding you.
Jane told Miss Stevens that Toby had smoked weed. By doing this she had GRASSED on him and can now be called a GRASS.
By Ulrikaumeko
Grass
Short vegetation that grows over large areas, usually green. Grass may vary in lenth, texture, width, and color. Most areas in front of a home are covered with grass.
You can try to smoke that grass, but I bet it won't do anything.
By Ivette
Grass
a snitch, some one who tells to police/orthorities on someones dodgey acts.