Also a term in British drug culture, meaning passing out or almost passing out due to excessive consumption of marijuana.

This is probably the worst case scenario as far as smoking weed is concerned and is not a pleasant experience. Many people who "whitey" tend to feel nauseous and may sometimes throw up. Others may feel the need to lie down or or may fall to the ground involuntarily. Although conscious to events around them, the person generally cannot be bothered to do anything other than lie in their space and stare at something. This can be a spot on a wall or, if they're lucky, a TV.

The person may well recover and be fine to move and talk again in around 20 minutes, or they may simply fall asleep. This event is actually quite rare, but depending on a person's tolerance, may happen quite frequently.