The crossword solution for the term 'IT DISAPPEARS WHEN YOU STAND' is 'LAP'. This is an acronym for 'Lowest Astronomical Point', which is a term used in astronomy to describe the lowest point in the sky that an object can reach. It is also used to describe the lowest point of the horizon that an observer can see. In other words, when you stand up, the horizon appears to be lower than when you are sitting down, and this is referred to as the 'LAP'.