What is a sheet or web supported by springs in a metal frame and used as a springboard?
Trampoline - a piece of equipment that has a sheet of strong cloth attached by springs to a metal frame, used for jumping up and down for exercise or as a sport - Merriam-Webster
Origin of TRAMPOLINE - Italian trampolino springboard, from trampol stilts, of Germanic origin; akin to Middle Low German trampen to stamp
First Known Use: 1798
Rihanna jumping on a trampoline is your new happy place. See the picture at MTV.com.