The phrase "groove thing" refers to something that has a great rhythm or beats that make you want to move and dance. It represents music or any activity that is enjoyable and gets you into a good groove or flow. Full definition
Between the big - screen trivia games and the big - screen, home - team - only replays (as lopsided as a Politburo show trial) and the big - screen commercials and the big - screen sneaker races and the big - screen cutaways of overserved burly girls shaking what appears to be a groove thing (only way larger) and the big - screen instructions to CHEER! (si.com)
If you're looking to wiggle, laugh, embrace feeling good in your body, and maybe even shake your groove thing — then, you have come to the right place. (bodylovetribe.com)