A newly discovered sex move in which a male/female becomes submerged in two bodies. This is done by inserting the top half of one's body in to another's asshole. The same is then done with bottom half of the body.
Teacher: Would you guys like to 50/50 with me in the middle?
2 Boys: Um... Yes!
A joint that is rolled up with about half weed and half tobacco. It makes the smoke much more light and easy to get a good smoke if you don't have a lot of green left. Note: 50/50s get you higher than you may think.
Yeah, we rolled a 50/50 and smoked it as we walked to our intramural soccer game.