Green Out: When a pot smoker has smoked a lot of weed in a short amount of time, or taken large hits of very good bud and passes out. Vision gets blurry, loss of hearing, and your balance gets so out of whack you don't know which way is up. This can happen with both newbies & long time smokers.
After three hits in a row off of the gravity bong, Clint fell over and had a green out. He woke up, drank some water & was fine.