1. What you do when you are in a heavy drug-related intoxication. This may be you passing out, or carrying out extreme, wierd and funny behaviour.
2. The point after taking a pill when you take a hit.
3. An annoying light-weight.
2. "This is a great pill, I'm completely smacking out"
3. "Look at him, he's only had 2 pints and a joint, and his behaviour is causing me great annoyance. He is such a smack out."