pogo stick
A jumping device made of a metallic stick with springs somewhere inside, and two footrests at the stick's base. Users stand on the footrests and use the springs to create a bouncing motion. The origins of the word 'pogo' is debated, but it's possible that its modern-version inventors Hans Pohlig and Ernst Gottschall (1920, Germany) combined the first two letters of their surnames to create the word.
Some modern designs have modified the springs or even replaced them altogether, such as with compressed air or a bow mechanism, and have achieved jumping heights of 6 feet or more (1.8 meter+). This has lead to the growth of using pogo sticks in an extreme sport and the development of the sport "extreme pogo" or "xPogo."