The term 'natural high' is a phrase used to describe the feeling of euphoria and joy that can be experienced without the use of drugs or alcohol. The crossword solution for this term is 'UPLAND, ' which is defined as an area of higher elevation, usually above the surrounding land. UPLAND can also refer to a region or area that is more elevated than the surrounding area. This term is often used to describe the feeling of being on top of the world, which is similar to the feeling of a natural high.