2. To prevent another from gaining access to the vagina. See also cock block.
3. In basketball, to prevent an opposing player from grabbing a rebound and scoring, by positioning oneself between the opponent and the basket.
2. Joan was tired of Tom's advances, so she called her girlfriends over to box him out.
3. No one could ever box out Wilt Chamberlain.
Adam: Chill, just Box Out for the rebound.
Also hotbox. Smoking pot in a confined and/or airtight area such as a car with all the windows wound up, room with all windows/doors closed, etc. Or even a tent with the zipper door closed.
Henry: Sure, John. Bring your car up to my back yard at 8 pm.
Johnny: Will do. And I'll bring some weed and my bong?
Henry: I've got two tinnies already, just bring the bong.
-When a woman steals the attention of a potential love interest away from another woman.
-the female version of the commonly known phrase "cock block"